Introduction Spectrometers

Introduction fiber-optic spectroscopy

Optical spectroscopy is a technique for measuring light intensity in the UV-, VIS-, NIR- and IR-range. Spectroscopic measurements are used in many different applications, such as color measurement, concentration determination of chemical components or electromagnetic radiation analysis. For more elaborate application information and setups, please click on the Application link.

How does a spectrometer work

A spectroscopic instrument, or spectrometer, generally consists of entrance slit, collimator, a dispersive element such as a grating or prism, focusing optics and detector. In a monochromator system there is normally also an exit slit, and only a narrow portion of the spectrum is projected on a one-element detector. In monochromators the entrance and exit slits are in a fixed position and can be changed in width. Rotating the grating scans the spectrum.

The development of micro-electronics during the 90’s in the field of multi-element optical detectors, such as charged coupled device (CCD) arrays and complementary metal-oxide semiconductor (CMOS) arrays, enabled the production of low cost scanners, CCD cameras, etc. These same CCD and CMOS detectors are now used in the Avantes AvaSpec line of spectrometers, enabling fast scanning of the spectrum, without the need for a moving grating.

Thanks to the need for fiber-optics in the communication technology, low absorption silica fibers have been developed. Similar fibers can be used as measurement fibers to transport light from the sample to the optical bench of the spectrometer. The easy coupling of fibers allows a modular build-up of a system that consists of a light source, sampling accessories and fiber-optic spectrometer. Furthermore, fiber-optics enable the introduction of sampling into harsh and difficult to access environments.

The low cost, modularity, flexibility and speed of measurement made possible by fiber-optic spectrometers have resulted in wide adoption of this technology in a variety of industries.

Optical bench design

The heart of most AvaSpec fiber-optic spectrometers is an optical bench with 37.5, 45, 50 or 75 mm focal length, developed in a symmetrical Czerny-Turner design. Light enters the optical bench through a standard SMA-905 connector and is collimated by a spherical mirror. A plain grating diffracts the collimated light after which a second spherical mirror focuses the resulting diffracted light. An image of the spectrum is projected onto a 1-dimensional linear detector array.
optical bench
Avantes' high-sensitivity spectrometers have a revolutionary optical bench design with multiple toroid mirrors which ensure that the full numerical aperture of the fiber entrance will be projected on the backthinned CCD array.

All of our optical benches have a number of components installed inside, allowing a wide variety of different configurations, depending on the intended application. The choice of these components, such as the diffraction grating, entrance slit, order-sorting filter, and detector coating have a strong influence on system specifications such as sensitivity, resolution, bandwidth and stray light. Each of these specifications is discussed in detail in the following paragraphs.

How to configure a spectrometer for your application

The modular AvaSpec line of instruments provides you with a number of configuration options to optimize the optical and spectroscopic performance of your instrument for your application.

This section will provide you with some guidance on how to choose the right grating, slit, detector and on other configuration options for your AvaSpec spectrometer.

Wavelength Range

When determining the optimal configuration of a spectrometer system, the wavelength range is a key parameter that defines the appropriate grating choice. If you are looking for a wide (broadband) wavelength range, we recommend the use of a 300 lines/mm grating, known as an A-type grating in the Avantes product line. For a smaller range (approximately 500 nm) but higher resolution, you might consider a 600 lines/mm, or B-type grating.

Higher lines/mm gratings (1200 – C-type, 1800 – D-type, 2400 – E-type, 3600 – F-type) provide higher resolution for applications that require this. Broadband gratings provide the greatest flexibility but may not provide the best performance for a specific application. Contact an Avantes Sales Engineer or representative for a recommended grating configuration.

Detector choice

The choice of your wavelength range along with the demands of your measurement speed and accuracy often suggests the appropriate detector for your application. Avantes offers a variety of different detector types, each with different sensitivity curves.

The AvaSpec instrument line is divided into multiple groups, based on general requirements:

  • The AvaSpec-Starline is comprised of general purpose UV/VIS instruments with low-cost CCD or CMOS detectors.
  • The AvaSpec Sensline is comprised of higher performance back-thinned CCDs and thermo-electrically cooled CCD UV/VIS instruments. These instruments are particularly better in the UV and NIR range, compared to standard CCD and CMOS detectors.
  • The AvaSpec NIRLine is comprised of instruments with InGaAs arrays for longer wavelength measurements, ranging from 900-2500 nm, suitable for various applications.
  • For applications where the size of the instrument is a critical factor, Avantes offers the CompactLine with spectrometers that have a small form factor.

The modularity and inter-compatibility of the AvaSpec line also make it possible to combine two or more detectors in a single instrument enclosure to provide optimal performance over a broad wavelength range. For example, an AvaSpec StarLine (UV/VIS) spectrometer can be combined with a NIRLine spectrometer to enable measurements from 200-2500 nm in a single instrument.

For high-speed applications, the 2048 pixel CMOS detectors in the AvaSpec-ULS2048CL-EVO from the StarLine are normally the best options. For low-light level applications such as fluorescence and Raman, the SensLine instruments may be the most appropriate. 

Optical Resolution & Slit Size

If a high optical resolution is required, you may want to consider a grating with higher lines/mm (1200 – C-type, 1800 – D-type, 2400 – E-type, 3600 – F-type), thus limiting the range of the instrument to a more narrow range. Additionally, it is advisable to consider a detector with 2048 or 4096 pixels and a small slit (10 or 25 µm). For the best resolution with all other criteria of lesser importance, the AvaSpec-ULS4096CL with a 10 micron slit is optimally suited.

Slit size is a key factor in determining both resolution and throughput into the optical bench. It is important to balance the need for resolution with the need for sensitivity and throughput into the optical bench. If resolution is optimized without considering the need for throughput, you may not have enough light to provide a stable measurement. As previously mentioned, for optimal resolution our smallest slit (10 microns) is recommended. If your application does not require the highest possible resolution and is not one that has an excess of light (laser measurement for example), we recommend that you consider as large a slit as possible to maximize throughput into the optical bench.

The AvaSpec-RS with replaceable slit makes your spectrometer a versatile instrument for both high-resolution and high-sensitivity measurements.

Sensitivity

When considering sensitivity, it is very important to distinguish between photometric sensitivity (how much light is needed for a detectable signal) and chemometric sensitivity (what absorbance difference level can still be detected).

Photometric Sensitivity 

For the best photometric sensitivity, a combination of a high-throughput optical bench and a high quantum efficiency (QE) detector is recommended. The instruments in the AvaSpec SensLine are specifically optimized for photometric sensitivity. 

Fluorescence applications, for example, require high photometric sensitivity. Avantes AvaSpec-HS2048XL is the highest performing instrument we offer for this application.

For Raman applications where the combination of resolution and sensitivity is required, we commonly reccomend our AvaSpec-HERO with thermoelectrical cooling.

To further enhance photometric sensitivity, we recommend the use of a detector collection lens (DCL-UV/VIS or DCL-UV/VIS-200), which is a cylindrical lens that focuses light from larger core fiber-optics and bundles down onto the smaller detector pixels. 

For additional photometric sensitivity, a larger slit or no slit and a 300 line/mm A-type grating to minimize light dispersion are available. Some more demanding applications also require thermoelectric cooling of the CCD detector (see product section AvaSpec-ULS2048LTEC and AvaSpec-HERO) to minimize noise and increase dynamic range at long integration times (up to 60 seconds).

Chemometric Sensitivity

To detect drastically different absorbance values, close to each other with maximum sensitivity, you need a high signal-to-noise (S/N) performance. The detectors with best S/N performance are again in the AvaSpec SensLine series spectrometers with the AvaSpec-HERO at the top of the line. The S/N performance can also be enhanced by averaging multiple spectra. The square root of the number of averages translates to the improvement in signal to noise.

Timing and Speed

The data capture process is inherently faster with linear detector arrays and no moving parts as compared to a monochromator design, however, there are optimal detectors for each application. For high-speed applications such as measurements involving pulsed lasers and light sources, we recommend the AvaSpec-ULS2048CL-EVO, AvaSpec-ULS2048-USB2, AvaSpec-ULS2048L-USB2 or the AvaSpec-FAST spectrometers. 

Each of these instruments supports high-speed data acquisition, with the capability of starting an acquisition within 1.3 microseconds of receiving an external trigger. The AvaSpec-FAST spectrometers support integration times as low as 0.5 milliseconds and the AvaSpec-ULS2048 and ULS2048L support 1.05 millisecond integration times. Since data transfer time is critical for these applications, Avantes’ unique Store-to-RAM mode enables on board storage of up to 5000 spectra to the instrument RAM buffer. 

The above parameters are the most important in choosing the right spectrometer configuration. Please contact our application engineers to optimize and fine-tune the system to your needs. The table below provides a quick reference guide for spectrometer selection for many common applications. The system recommendations in this table are for simple configurations of mostly single channel spectrometers.

Table 1 - Quick reference guide for spectrometer configuration

Application

AvaSpec-type

Grating

WL range (nm)

Coating

Slit

FWHM Resolution (nm)

DCL

>OSF

OSC

Biomedical

ULS2048CL

NB

500-1000

-

50

1.2

-

475

-

Chemometry

ULS2048CL

UA

200-1100

-

50

2.3

-

-

OSC-UA

Color

ULS2048CL

BB

360-780

-

200

4.5

X/-

-

-


Fluorescence

ULS2048x64TEC
ULS2048XL

VA, VB, UB

350-1100
300-800

-

200

9.2
4.6

X

305

OSC

HS2048XL

HS-500-0.33

200-1160

-

200

10.0

-

-

OSC

Fruit sugar

ULS-2048CL

IA

800-1100

-

50

6.4

X

600

-

Gemology

ULS2048

VA

350-1100

-

25

1.2

X

-

OSC

High resolution

ULS2048CL

VD

600-700

-

10

0.12

-

550

-

ULS4096CL

VD

600-700

-

10

0.05

-

550

-

High UV/NIR-Sensitivity

HS2048XL

HS-500-0.33

200-1160

-

200

10.0

-

-

OSC

Irradiance

ULS2048CL

UA

200-1100

DUV

50

2.3

X/-

-

OSC-UA

Laserdiode

ULS4096CL

NC

700-800

-

10

0.18

-

600

-

LED

ULS2048CL

VA

350-1100

-

25

1.2

X/-

-

OSC

LIBS

ULS4096CL

D, E, F

200-900

DUV

10

0.09

-

-

-

Raman

ULS2048LTEC
ULS2048X64TEC

NC

780-930

-

25

0.3

X

600

-

Solar

ULS2048XL

VA

300-1100

-

50

2.5

-

305

OSC

Thin films

ULS2048CL

UA 

200-1100

DUV

100

4.6

X

-

OSC-UA

UV/VIS/NIR

ULS2048CL

UA

200-1100

DUV

25

1.2

X/-

-

OSC-UA

ULS2048XL

UA

200-1100

-

25

1.5

-

-

OSC-UA

NIR

NIR512-1.7TEC

NIR200-1.5

1000-1750

-

25

6.0

-

1000

-

NIR256-2.5TEC

NIR100-2.5

1000-2500

-

50

15.0

-

1000

OSC-NIR

How to choose the right grating

A diffraction grating is an optical element that separates incident polychromatic radiation into its constituent wavelengths. A grating consists of series of equally spaced parallel grooves formed in a reflective coating deposited on a suitable substrate.

gratings.jpg

The way in which the grooves are formed separates gratings into two types: holo-graphic and ruled. The ruled gratings are physically formed onto a reflective surface with a diamond on a ruling machine. Gratings produced from laser constructed interference patterns and a photolithographic process are known as holographic gratings.

Avantes AvaSpec spectrometers come with a permanently installed grating that must be specified by the user. Additionally, the user needs to indicate what wavelength range needs to reach the detector. Sometimes, the specified usable range of a grating is larger than the range that can be projected on the detector. In order to cover a broader range, a dual or multi-channel spectrometer can be chosen. In this configuration each channel may have different gratings covering a segment of the range of interest. In addition to broader range, a dual or multi-channel spectrometer also affords higher resolution for each channel.

A grating selection table for each spectrometer type is shown in the spectrometer platform section. Table 2 illustrates how to read the grating selection table. The spectral range to select in Table 2 depends on the starting wavelength of the grating and the number of lines/mm; the higher the wavelength, the bigger the dispersion and the smaller the range to select.

Below that, each grating's efficiency curve is shown. When looking at the grating efficiency curves, please realize that the total system efficiency will be a combination of fiber transmission, grating and mirror efficiency, detector quantum efficiency and coating sensitivities. Our dual-blazed grating is a 300 lines/mm broadband grating (covering 200-1100 nm) that has optimized efficiency in both UV and NIR. 

 

grating selection

Grating Efficiency Curves
300 lines/mm gratings
300 lines per mm gratings
600 lines/mm gratings
600 lines per mm gratings
1200 lines/mm gratings
1200 lines per mm gratings
1800 lines/mm gratings
1800 lines per mm gratings
2400 lines/mm gratings
2400 lines per mm gratings
3600 lines/mm gratings
3600 lines per mm gratings
HS 500 lines/mm gratings
HS 500 lines per mm gratings
HS 600 lines/mm gratings
HS 600 lines per mm gratings
HS 830-1000 lines/mm gratings
HS 830 1000 lines per mm gratings
HS 1200 lines/mm gratings
HS 1200 lines per mm gratings
HSC 300-400 lines/mm gratings
HSC 300 400 lines per mm gratings
HSC 600-830 lines/mm gratings
HSC 600 830 lines per mm gratings
HSC 1200-2400 lines/mm gratings
HSC 1200 2400 lines per mm gratings
NIR 75-100 lines/mm gratings
NIR 75 100 lines per mm gratings
NIR 150 lines/mm gratings
NIR 150 lines per mm gratings
NIR 200-300 lines/mm gratings
NIR 200 300 lines per mm gratings
NIR 400-600 lines/mm gratings
NIR 400 600 lines per mm gratings

 

Grating Dispersion Curves
300 lines/mm gratings
Avabench75 2048-pag14
600 lines/mm gratings
disp 600
1200 lines/mm gratings
disp 1200
1800 lines/mm gratings
disp 1800
2400 lines/mm gratings
disp 2400
3600 lines/mm gratings
disp 3600

How to select the optimal optical resolution

Optical resolution is defined as the minimum difference in wavelength that can be separated by the spectrometer. For separation of two spectral lines, it is necessary to image them at least two array pixels apart.

Because the grating determines how far different wavelengths are separated (dispersed) at the detector array, it is an important variable for the optical resolution. The other important parameter is the width of the light beam entering the spectrometer. This is basically the installed fixed entrance slit in the spectrometer, or the fiber core when no slit is installed.

For AvaSpec spectrometers, the available slit widths are 10, 25, 50, 100, 200 µm wide x 1000 µm high and 500 µm wide x 2000 µm high. The slit image on the detector array for a given wavelength will cover a number of pixels. For two spectral lines to be separated, it is necessary that they be dispersed over at least this image size plus one pixel. When large core fibers are used, the resolution can be improved by a slit of smaller size than the fiber core. This effectively reduces the width of the light beam entering the spectrometer optical bench.

The influence of the chosen grating and the effective width of the light beam (fiber core or entrance slit) are shown in the tables provided for each AvaSpec spectrometer instrument.

In the table below, the typical resolution for the AvaSpec-ULS2048CL-EVO can be found. Please note that for the higher lines/mm gratings the pixel dispersion varies along the wavelength range and gets better towards the longer wavelengths.

The resolution in this table is defined as FWHM (Full Width at Half Maximum), which is defined as the width of the peak at 50% of the maximum intensity in nm.

Graphs with information about the pixel dispersion can be found in the gratings section as well, so you can determine the optimal grating and resolution for your specific application.

For larger pixel-height detectors (3648, 2048L, 2048XL) in combination with thick fibers (>200 µm) and a larger grating angle, the actual FWHM value can be 10-20% higher than the value in the table. Small core diameter fibers are recommended for the highest resolution.

All data in the resolution tables are based on averages of actual measured data (with 200 µm fibers) from our quality control system during the production process. A typical standard deviation of 10-25% (depending on the slit diameter and the grating) should be taken into account. For 10 µm slits, the typical standard deviation is somewhat higher, which is inherent to the laws of physics. The peak may fall exactly within one pixel, but may cover two pixels, causing lower measured resolution.

The placeable slit feature is available on all ULS and NIR spectrometers. The spectrometers come with one installed slit and a slit kit that includes all four slit sizes, so you can opt for higher resolution (25 µm slit), higher throughput (200 µm slit) or somewhere in between (50 or 100 µm slits).

 

Resolution (FWHM in nm) for the AvaSpec-ULS2048CL-EVO

Slit size (µm)

Grating (lines/mm)

10

25

50

100

200

500

300

0.80-0.90*

1.10-1.20*

2.30

4.60

9.00

20.0

600

0.40-0.50*

0.36

1.15

2.31

4.50

10.0

830

0.28

0.40

0.80

1.60

3.20

8.0

1200

0.18-0.22*

0.29

0.61

1.18

2.20

5.4

1800

0.10-0.16*

0.19

0.35-0.42*

0.80

1.60

3.6

2400

0.08-0.11*

0.10-0.15*

0.28

0.55

1.10

2.7

3600

0.05-0.08*

0.10

0.18

0.38

0.75

1.8

*depends on the starting wavelength of the grating; the higher the wavelength, the bigger the dispersion and the higher the resolution

Detector arrays

The AvaSpec line of spectrometers can be equipped with several types of detector arrays. Presently, we offer silicon-based CCDs, back-thinned CCDs, and CMOS arrays for the 200-1100 nm range. A complete overview of each is given in the following section: "Sensitivity".
For the NIR range (1000-2500 nm), InGaAs arrays are implemented.

All detectors are tested in incoming goods inspection, before they are used in our instruments. Avantes offers full traceability on the following detector specifications:

• Dark noise
• Signal to noise
• Photo response non-uniformity
• Hot pixels

StarLine and CompactLine CMOS detectors (AvaSpec-ULS2048CL/4096CL)

Both CCD (charge-coupled device) and CMOS (complementary metal-oxide semiconductor) detectors start at the same point: they convert light into electrons, just with different technologies. In the last years, CMOS sensors have improved to a point where they reach near parity with CCD devices.

Looking to the future, the CMOS detectors seem to take over the standard CCD technology in general purpose spectrometers. In general, the CMOS detectors have a good UV response (without the need of using UV-enhancement coatings) and a higher response in the NIR range. 

The overall sensitivity tends to be somewhat lower than with CCD technology, though. 

pagina 16 Starline detectoren vrijstaand

 

 

SensLine Back-thinned CCD Detectors (AvaSpec-ULS2048x16/x64/XL/HS1024x58/122)

For applications requiring high quantum efficiency in the UV (200-350 nm) and NIR (900-1160 nm) range, combined with good S/N and a wide dynamic-range, back-thinned CCD detectors are the right choice. Both uncooled and cooled backthinned CCD detectors are offered, the uncooled backthinned CCD detector has 2048 pixels with a pixel pitch of 14 µm and a height of 500 µm, to have more sensitivity and a better S/N performance.
For even better sensitivity and S/N the cooled backthinned CCD detector is the best choice, it has 1024 pixels, each of them with 58 or 122 vertically binned pixels, giving an effective detector height of 1.4 mm or nearly 3.0 mm

+  An advantage of the back-thinned CCD detector is the good UV and NIR sensitivity, combined with good S/N ratio and dynamic range.

-  A disadvantage is the relatively higher cost.

pagina 16 Senseline detectoren vrijstaand

 

InGaAs linear image sensors (AvaSpec-NIR256/512)

The InGaAs linear image sensors deliver high-sensitivity in the NIR wavelength range. The detector consists of a charge-amplifier array with CMOS transistors, a shift-register and timing generator. For InGaAs detectors, the dynamic range is limited by the dark noise. No cooling is required for ranges up to 1.75 µm and these detectors are available in both 256 and 512 pixels. Detectors for the extended range (2.0-2.5 µm) all have 2-stage thermoelectric cooling (TEC) to reduce dark noise and are available in 256 and 512 pixel versions.

Seven detector versions are available:

  • 256/512 pixel non-cooled InGaAs detector for the 900-1750 nm range
  • 256/512 pixel cooled InGaAs detector for the 900-1750 nm range
  • 256/512 pixel 2-stage cooled Extended InGaAs detector for the 1000-2200 nm range

pagina 16 Nirline detectoren vrijstaand

Sensitivity

The sensitivity of a detector pixel at a certain wavelength is defined as the detector electrical output per unit of radiation energy (photons) incident to that pixel. With a given A/D converter, this can be expressed as the number of counts per mJ of incident radiation.

The relation between light energy entering the optical bench and the amount hitting a single detector pixel depends on the optical bench configuration. The efficiency curve of the grating used, the size of the input fiber or slit, the mirror performance and the use of a detector collection lens (DCL) are the main parameters.

With a given setup, it is possible to perform measurements over about six to seven decades of irradiance levels. Some standard detector specifications can be found in the detector specifications table.

Optionally, a cyllindrical DCL (detector collection lens) can be mounted directly on the detector array. The quartz lens (DCL-UV/VIS for AvaSpec-ULS2048) will increase the system sensitivity by a factor of 3 to 5, depending on the fiber diameter used. The DCL-UV/VIS-200 can be used for our spectrometers with larger pixel heights to provide a better vertical distribution of light focusing on the detector and is primarily suitable for fiber diameters larger than 200 µm and round- to-linear assemblies.
Our SensLine series has the most sensitive detectors out of all of our instrument lines, as it includes back-thinned and thermoelectrically cooled (TEC) detectors. 

In the tables below, the UV/VIS detectors are depicted with their specifications. Additional information on how those specifications are determined is listed in the following paragraphs. 

Pixel well depth (electrons)

This value is specified by the detector supplier and defines how many electrons can fit in a pixel well before it is saturated. This value determines the best reachable signal-to-noise (S/N) ratio (=√(pixel well depth)).

Sensitivity in photons/count @ 600 nm

This is the number of photons of 600 nm that are needed to generate one count of signal on a 16-bit AD converter. The lower this number, the better the sensitivity of the detector. The calculation of the number of photons/count is (pixel well depth in electrons)/16-bit AD/quantum efficiency @ 600 nm.

Sensitivity in counts/µW per ms integration time

Sensitivity here is for the detector types currently used in the UV/VIS AvaSpec spectrometers as output in counts per ms integration time for a 16-bit AD converter. To compare the different detector arrays, we have them all built up with an optical bench with a UA 300 lines/mm grating covering 200-1100 nm, a DCL if applicable, and a 50 µm slit.

The measurement setup for 350-1100 nm has a 600 µm fiber connected to an AvaSpere-50-LS-HAL, equivalent to an optical power of 1.14 µW. For the UV/VIS measurement at 220-1100 nm, we connected the 600 µm fiber to an AvaLight-DHS through a CC-VIS/NIR diffuser, equivalent to 2.7 µW power.

Peak wavelength and QE @ peak

The peak wavelength is provided by the detector supplier as well as the quantum efficiency (QE), defined as the number of electrons generated by one photon.

Signal to noise (S/N)

Signal to noise (S/N) is measured for every detector at Avantes’ quality control inspection and defined as the illuminated maximum S/N in root mean square (RMS) for the shortest integration time. The RMS is calculated over 100 scans.

Dark noise

Dark noise is measured for every detector at Avantes’ quality control inspection and defined as the non-illuminated noise in RMS (root mean square) for the shortest integration time. The RMS is calculated over 100 scans.

Dynamic range

The dynamic range is defined as the (maximum signal level-baseline dark level)/dark noise RMS.

Photo Response Non-Uniformity (PRNU)

Photo Response Non-Uniformity (PRNU) is defined as the maximum difference between output of pixels when uniformly illuminated, divided by average signal of those pixels.
PRNU is measured for every detector at Avantes’ quality control inspection.

Frequency

The frequency is the clock frequency at which the data pixels are clocked out through the AD-converter.

 

Detector specifications (based on a 16-bit AD converter)

StarLine SensLine

Detector

HAM-2048CL

HAM-4096CL

SONY2048L

HAM-2048XL

HAM-1024x58

Type

CMOS linear array

CMOS linear array

CCD linear array

Back-thinned CCD array

Cooled back-thinned CCD array

# Pixels, pitch

2048, 14 µm

4096, 7 µm

2048, 14 µm

2048, 14 µm

1024 x 58, 24 µm

Pixel width x height (µm)

14 x 200

7 x 200

14 x 200

14 x 500

24 x 24 ( total height 11.4 mm)

Pixel well depth (electrons)

80,000

80,000

90,000

200,000

1,000,000

Sensitivity Photons/count @600 nm

2

2

2

4

16

Sensitivity
in counts/µW per ms integration time

375,000
(AvaSpec-ULS2048CL)

218,000
(AvaSpec-ULS4096CL)

470,000
(AvaSpec-ULS2048L)

460,000
(AvaSpec-ULS2048XL)

445,000
(AvaSpec-HERO)

Peak wavelength

700 nm

700 nm


450 nm

650 nm

650 nm

QE (%) at peak

80%

80% 40% 78% 92%

Signal/Noise

300:1

335:1

300:1

525:1

1200:1

Dark noise (counts RMS)

16

16

20

5

2

Dynamic Range

4000

4000

3300

13,700

40,000

PRNU**

± 5%

± 5%

± 5%

± 3%

± 3%

Wavelength range (nm)

200-1100

200-1100

200-1100

200-1160

200-1160

Frequency

6 MHz

6 MHz

2 MHz

1 MHz

250 kHz

** Photo Response Non-Uniformity = max difference between output of pixels when uniformly illuminated, divided by average signal

 

Detector Spectral Sensitivity Curves

Sensitivity UV-VIS-NIR-2

sensitivity_uv-vis-nir.jpg



In the next table, the specifications for the NIR spectrometers are given, followed by the spectral response curve for the different detector types.

 

NIR sensitivity

For NIR detectors, two different modes are available: high-sensitivity (HS) and low-noise (LN). The default setting is the HS mode, which provides a better signal at a shorter integration time. The other mode of operation, the LN mode, provides a better S/N (signal-to-noise) performance.

Sensitivity, S/N, dark noise and dynamic range are given as HS and LN values.

 

NIR detector specifications

NIRLine
Detector

HAM-256-1.7

HAM-512-1.7 SU-256-1.7 SU-521-1.7 HAM-256-2.5 HAM-512-2.5
Type

Linear InGaAs array

Linear InGaAs array Linear InGaAs array
with 1-stage TE cooling

Linear InGaAs array 
with 1-stage TE cooling

Linear InGaAs array
with 2-stage TE cooling
Linear InGaAs array
with 2-stage TE cooling
# Pixels, pitch

256.50 µm

512.25 µm

256.50 µm

512.25 µm

256.50 µm

512.25 µm 

Pixel width x height (µm)

50 x 500

25 x 500

50 x 500

25 x 500

50 x 250

25 x 250

Sensitivity HS
in counts/µW per ms

8,200,000 (integral 1000-1750 nm)

3,880,000 (integral 1000-1750 nm) 4,800,000 (integral 1000-1750)

2,500,000 (integral 1000-1750 nm)

990,000 (integral 1000-2500 nm)

480,000 (integral 1000-2500 nm)

Signal/
Noise (HS)

1900:1

1900:1

5000:1

5000:1

1800:1

1900:1

Dark noise HS (counts RMS)

16

16

16

16

16

 15

Dynamic Range HS

6000

6000

4900

4900

 3500

4300

Sensitivity LN
in counts/µW per ms
469,000
(integral 1000-1750 nm)
222,000
(integral 1000-1750 nm)
160,000
(integral 1000-1750 nm) 
83,000
(integral 1000-2500 nm)
55,000
(integral 1000-2500 nm)
26,600
(integral 1000-2500 nm)

Signal/Noise (LN)

5000:1 5000:1 5000:1 5000:1 4000:1 3700:1

Dark noise LN (counts RMS)

12 12 12 12 12 13 

Dynamic Range LN

9000 9000 7600 7600 4500 5100

Peak wavelength

1550 nm 1550 nm 1500 nm 1500 nm 3200 nm 3200 nm

QE (%) @ peak

90% 90% 70% 70% 65% 65%

PNRU**

±5%

±5%

10% 10%

±5%

±5%

Defective pixels (max)

0

0

0

0

12

26 

Wavelength range (nm)

900-1750

900-1750

900-1750

900-1750

1000-2500

1000-2500

Frequency

500 kHz

500 kHz

1.2 mHz 1.2 mHz

500 kHz

500 kHz

** Photo-Response Non-Uniformity

 

NIR Detector Sensitivity Curves

sensitivityCatIX NIR

Stray light and second-order effects

Stray light

Stray light is radiation of undesired wavelengths that activates a signal at a detector element. Sources of stray light can be:

  • Ambient light
  • Scattered light from imperfect optical components or reflections of non-optical components
  • Order overlap

Avantes' symmetrical Czerny-Turner optical bench designs favor stray light rejection as opposed to crossed designs. Additionally, Avantes AvaSpec-ULS (ultra-low stray light) spectrometers have a number of internal measures to reduce stray light from zero order and backscattering.

When working at the detection limit of the spectrometer system, the stray light level from the optical bench, grating and focusing mirrors will determine the ultimate limit of detection. Most gratings used are holographic gratings, known for their low level of stray light. Stray light measurements are conducted using a halogen light source and long-pass or band-pass filters. Typical stray light performance for the AvaSpec-ULS and a B-type grating is <0.04% at 250-500 nm.

Second-order effects

Second-order effects, which can play an important role for gratings with low groove frequency and therefore a wide wavelength range, are usually caused by the second-order diffracted beam of the grating. The effects of these higher orders can often be ignored, but sometimes need to be addressed using filtering. The strategy is to limit the light to the region of the spectra, where order overlap is not possible.

Second-order effects can be filtered out, using a permanently installed long-pass optical filter in the SMA entrance connector or an order-sorting coating on a window in front of the detector. The order-sorting coatings on the window typically have one long-pass filter (600 nm) or 2 long-pass filters (350 nm and 600 nm), depending on the type and range of the selected grating.

IMG 9831

Order-sorting window in holder

In the table below, a wide range of optical filters for installation in the optical bench can be found. The filter types that are 3 mm thick give much better second-order reduction than the 1 mm filters. The use of the following long-pass filters is recommended: OSF-475-3 for grating NB and NC, OSF-515-3/550-3 for grating NB and OSF-600-3 for grating IB. For backthinned detectors, such as the 2048XL and 1024x58/122 we recommend an OSF-305 Filter, when the starting wavelength is 300 nm and higher.


In addition to the order-sorting coatings, we apply partial DUV coatings on the Sony 2048 detectors to avoid second-order effects from UV response and to enhance sensitivity and decrease noise in the visible range.

 

Filters installed in AvaSpec spectrometer series

OSF-XXX

Permanently installed order-sorting filter @ XXX nm
(XXX = 305, 395, 475, 515, 550, 600, 850)

OSC

Order-sorting coating with 600 nm long-pass filter for BB (>350 nm) and VB gratings

OSC-UA

Order-sorting coating with 350 and 600 nm long-pass filter for UA/VA gratings. Linear Variable Filter for ULS benches

OSC-UB

Order-sorting coating with 350 and 600 nm long-pass filter for UB or BB (<350nm) gratings

OSC-HS500

Order-sorting coating with 350 and 600 nm long-pass filter for HS500 gratings in AvaSpec-HS

OSC-HS900

Order-sorting coating with 600 nm long-pass filter for HS900 gratings in AvaSpec-HS

OSC-HS1000

Order-sorting coating with 350 nm long-pass filter for HS1000 gratings in AvaSpec-HS

OSC-HSC300

Order-sorting coating for use with grating HSC0300-xx

OSC-HSC600

Order-sorting coating for use with grating HSC0600-xx

OSC-NIR

Order-sorting coating with 1400 nm long-pass filter for NIR100-2.5 and NIR150-2.0 gratings

Thermal stability

All AvaSpec spectrometers have no moving parts inside and are extremely robust and stable.

The thermal stability of our spectrometers is part of our comprehensive quality control (QC) procedure and therefore closely monitored during the production and assembly process. All of our spectrometers undergo overnight thermal cycling, during which wavelength shift, intensity drop and spectral tilt are registered and checked against our QC acceptance norm.

More specifically, the following test are being carried out during the thermal cycling from 15°C to 25°C to 35°C back to 25°C:

Full Width at Half Maximum (FWHM)

During the thermal cycling, the average FWHM value is measured and has to fit with a certain standard deviation within the QC acceptance norm for the different configurations, which can be found in our catalog.

Peakshift

During thermal cycling, the shift of peaks is monitored and depicted as shift in pixels per °C. Depending on the grating angle, the maximum allowed peakshift is defined, for most gratings the below values are the QC acceptance norm. For gratings with many lines/mm starting at high wavelengths (VD, VE), the peak shift can double.

Intensity stability and Spectral tilt

Temperature sensitivity on the intensity axis can have a number of reasons. First, the CCD detector itself has a temperature dependency, for most detectors there are black pixels that are read out and are subtracted from the rest of the data pixels, the so-called "Correct for Dynamic Dark" (CDD). However, CDD will not correct spectral tilt, which is partially a detector property as well. The aluminum optical bench and the optical components are engineered in such a way that the thermal expansion does not lead to a large increase in tilt or sensitivity.

For most spectrometers, the average intensity increase/decrease is within ±4% for ±10°C thermal cycling.

In the figure below, a typical test result for a thermal cycling can be seen.

Thermal-stability

Spectometer platforms

ULS4096CL EVO web

AvaSpec StarLine 

The AvaSpec StarLine family of instruments is compromised of high-performance spectrometers which exceed the demands of most general spectroscopy applications. The StarLine includes high-speed instruments for process control (AvaSpecULS2048CL-EVO and AvaSpec-FAST series), high-resolution instruments for demanding measurements like atomic emission (AvaSpec-ULS4096CL-EVO) and versatile instruments for common applications such as irradiance and absorbance chemistry (AvaSpec-ULS2048 & Avaspec-ULS2048L). This instrument line offers an array of solutions for varied uses, while providing excellent price-to-performance ratios.

The AvaSpec-ULS2048CL-EVO and AvaSpec-ULS4096CL-EVO are based on CMOS arrays and can measure wavelengths from 200 to 1100 nm. The AvaSpec-FAST series of instruments is specially designed for high-speed acquisitions such as pulsed light source and laser measurements. 

Instruments in the AvaSpec StarLine family are designed to perform in a variety of applications such as:

  • Reflection and transmission measurements for optics, coatings and color measurements
  • Irradiance and emission measurements for environmental industries, light characterization, and optical emission spectroscopy
  • High-speed measurements for process control, LIBS or laser/pulsed source characterization
  • Absorbance chemistry

AvaSpec StarLine instruments are fully integrated with Avantes’ modular platform, allowing them to function stand-alone, or as multi-channel instruments. These products are fully compatible with other AvaSpec instruments in our AvaSpec SensLine and NIRLine. The entire AvaSpec StarLine is available as an individual lab instrument or an OEM module for integration into customers’ existing systems.

The StarLine instruments are available with our standard ultra-low stray light (ULS) optical bench (75 mm focal length) and with a number of premium options, such as irradiance/intensity and non-linearity callibration. 

 

New Mini HR

AvaSpec CompactLine

In cases where size matters, the AvaSpec CompactLine family offers spectrometers with the smallest form factor. This enables easier integration of these spectrometers into machines or handheld devices. The AvaSpec CompactLine is based on the AvaSpec-ULS2048CL and AvaSpec-ULS4096CL of the StarLine family. Squeezing down the size hardly compromises the performance of these instruments, but limits the customer a bit in configurations available. Customization is possible for an adequate number of needed instruments. Therefore, the CompactLine is especially well-suited for OEM customers looking to integrate a spectrometer into their own instrument. 



HERO USB3 front

AvaSpec SensLine

The AvaSpec SensLine family of products is Avantes’ response to customers who require higher performance for demanding spectroscopy applications such as fluorescence, luminescence and Raman. The AvaSpec SensLine product line includes high-sensitivity, low-noise spectrometers. Some of the instruments are based on back-thinned detector technology, of which some feature high-performance, thermoelectrically cooled detectors. The othe rmodels are based on standard CCDs, upgraded to high-performing instruments as a result of Avantes' unique detector cooling technology. The back-thinned CCD detectors featured in the AvaSpec Sensline product family are high quantum efficiency detectors with excellent response in the UV, VIS and NIR range from 200 to 1160 nm. 

AvaSpec SensLine instruments are fully integrated with Avantes’ modular platform, allowing them to function standalone, or as multi-channel instruments. These products are fully compatible with other AvaSpec instruments in our AvaSpec StarLine and AvaSpec NIRLine product families. The entire AvaSpec SensLine is available as a lab instrument or an OEM module for integration into a customers’ existing system.

Avantes’ innovative ultra-low stray light (ULS), revolutionary high-sensitivity (HS) and the optimal compromise (HSC) optical benches are the core optical technologies in the AvaSpec SensLine. These highly stable optical benches combined with our high-performance circuit boards make for high-performance instruments at affordable prices.

All members of the AvaSpec SensLine are designed to provide performance features such as:

  • High stability
  • High sensitivity
  • High-speed acquisition
  • Low noise

 

 

 

AvaSpec NIR256 2.5 HSC

AvaSpec NIRLine

The AvaSpec NIRLine instruments are high-performance, near-infrared spectrometers that are optimized for the demands of measuring long wavelengths. This line provides leading-edge performance for dispersive NIR instruments with toroidal focusing mirrors and dynamic dark correction (DDC) for enhanced stability. The NIRLine is comprised of both thermoelectrically cooled and uncooled instruments. The AvaSpec-NIR256/512-1.7 features an uncooled 256 or 512 pixel InGaAs detector. All other instruments in the NIRLine have thermoelectric, peltier-cooled InGaAs detectors that support cooling down to -25°C against ambient.

AvaSpec NIRLine instruments are fully compatible with our AvaSpec StarLine and SensLine spectrometers. Avantes’ AvaSpec NIRLine instruments are available as laboratory instruments or OEM modules and a number of premium options such as irradiance/intensity and non-linearity calibration are available as well.

The AvaSpec NIRLine of instruments are designed to perform in a variety of applications such as:

  • Moisture content measurement of liquids, solids and powders for inline and quality control purposes
  • Quantitative and qualitative measurement of volatile organics such as ethanol, and methanol
  • Plastic characterization and material identification
  • Irradiance measurements, such as solar monitoring
  • Qualitative measurements of feed and food

Introduction Software

Introduction Software

AvaSoft is a software package that can be used to control all Avantes spectrometers and a wide range of accessories. The latest version can be used with the latest Windows versions. Since the initial version of AvaSoft in 1996, a major upgrade has been released at least once a year, featuring new options and possibilities.

Different versions

Our state of the art modular software is available as a scalable platform:

  • AvaSoft-Basic: Everything needed for basic measurements and controlling your AvaSpec series spectrometer, including basic data acquisition. Basic allows you to save and display data in the following modes: scope, transmission, absorption and relative irradiance.
  • AvaSoft-Full: Includes all possibilities of AvaSoft-Basic and adds many other options, such as history channel functions, auto-calibration procedures and external triggering.
  • Application add-on modules for AvaSoft-Full enable special measurement procedures: color measurements, absolute irradiance, chemometrics, process control and real-time export to Excel.
  • AvaSoft-All, which includes AvaSoft-Full and all application modules in one package.
  • Dynamic Link Library (DLL) interface packages with support for basic spectrometer control, color measurements and irradiance measurements.

Download & try

The most recent release of AvaSoft can be downloaded free of charge. The downloaded AvaSoft can be used by customers who already have an AvaSpec spectrometer and want to update their software version, but also by anyone who wants to try out the AvaSoft-FULL version and/or add-on applications. When no spectrometer is connected to the computer, AvaSoft will start in demo-mode, making it ideal to try out our software.
In demo-mode, the software will work as AvaSoft-Full, making it possible to test spectrometer functions and display and analyze spectra offline.


Introduction Light Sources

Introduction light sources

For applications such as transmission, absorption and reflection, illumination sources are needed. Avantes offers a wide range of different light sources, to suit your specific needs. An overview of the different options can be found on this page.

Different types of light sources

Tungsten Halogen light sources are mostly used to do measurements in the visible and NIR range. AvaLight Halogen sources provide a very stable output combined with long bulb lifetime. The high-stability enables their use in reflection and transmission configurations or as an irradiance calibration light source. Most importantly, the Halogen light’s spectral output is a smooth black body curve which provides for maximized dynamic range.

Avantes Deuterium light sources are known for their stable output and are used for UV absorption or reflection measurements. These can also be used as irradiance calibration sources due to their high-stability. The standard AvaLight-DH-S mixes the Halogen light with the Deuterium light, thus producing a wide spectral range light source. The output spectrum of Deuterium light sources exhibits several peaks, with a prominent peak at 656 nm. The AvaLight-DH-S-BAL incorporates a dichroic beam splitter installed to minimize these peaks, providing a smooth spectrum from 200-2500 nm.

Our pulsed Xenon light source is used in applications where a long lifetime and high output power is needed, such as in fluorescence measurements. This is an affordable UV source, but the spectral output is not as smooth and continuous as the AvaLight Halogen and Deuterium light sources. LED light sources provide high power at a precise wavelength. A typical application for AvaLight-LED sources is fluorescence. They provide long lifetime, short warm-up time and high-stability.

For wavelength calibration Avantes offers a variety of sources including Argon, Mercury- Argon, Neon, Zinc and Cadmium. All Avantes spectrometers are factory wavelength calibrated and do not require recalibration as they have fixed slits and optics. For those customers who wish to do their own calibrations, the AvaLight-CAL light sources can be used for recalibration purposes. For auto-calibration AvaSoft-Full provides a calibration procedure to make this easy.

Table Light sources

Application

Wavelength Range

Type

Principle

Product

Color / VIS / NIR

360-2500 nm

Tungsten Halogen

Continuous

AvaLight-HAL(-S)

DUV

190-400 nm

Deuterium

Continuous

AvaLight-D-S-DUV

UV

215-400 nm

Deuterium

Continuous

AvaLight-D-S

UV/VIS/NIR refl./abs.

215-2500 nm

Deuterium/Halogen

Continuous

AvaLight-DH-S-(BAL)

UV/VIS/NIR absorption

200-2500 nm

Deuterium/Halogen

Continuous

AvaLight-DHc

UV/VIS

200-1000 nm

Xenon

Pulsed

AvaLight-XE

Fluorescence

Multiple possible

LED

Continuous

AvaLight-LED

Wavelength Calibration

253-1704 nm

Mercury-Argon

Neon / Argon

Continuous

AvaLight-CAL

 

Irradiance Calibration

 

200-700 nm

Zinc / Cadmium

Continuous

AvaLight-CAL-CAD/Zinc

360-2500nm

Tungsten Halogen

Continuous

AvaLight-HAL-CAL

200-1100nm

Deuterium/Halogen

Continuous

AvaLight-DH-(BAL)-CAL

Radiance Calibration 360-2500 Tungsten Halogen Continuous AvaSphere-50-LS-HAL-CAL

Spectral distribution light sources

The spectral distribution of the different light source is given in this figure.

allspec2


Introduction Fiber Optics

Introduction Fiber-Optics

The use of fiber-optics as light guidance allows a great modularity and flexibility in the setup of an optical measurement system. Optical fibers can be made of many materials, such as plastic, glasses and silicates (SiO2). For high quality fiber-optics, as used in spectroscopic applications, synthetic fused silica (amorphous silicon dioxide) is used, that can be intentionally doped with trace elements to adjust the optical properties of the glass.

Basic principles

The basic principle of light transport through an optical fiber is total internal reflection. This means that the light within the numerical aperture of a fiber (NA = input acceptance cone) will be reflected and transported through the fiber. The size of the numerical aperture depends on the materials used for core and cladding.

Two basic types of silica fibers can be distinguished; single-mode and multi-mode fibers, depending on the propagation state of the light, traveling down the fiber. For most spectroscopic applications multi-mode fibers are used. Multi-mode fibers can be divided into 2 subcategories, step-index and graded-index. A relatively large core and high NA allow light to be easily coupled into the fiber, which allows the use of relatively inexpensive termination techniques. Step-index fibers are mainly used in spectroscopic applications.

Graded-index multimode fibers have a refractive index gradually decreasing from the core out through the cladding. Since the light travels faster in material with lower refractive index, the modal dispersion (amount of pulse-spreading) will be less.
These graded-index fibers are mainly used in telecommunication application, where dispersion at long distance (2-15 km) plays an important role.

Product codes

For example FC-20UVIR200-3-BX-SR
A product code is designed as follows:

 Type of product Total number of fibers Wavelength  Fiber core diameter Overall length Jacketing Other options

FC = standard fiber cable
FCB = bifurcated fiber
FCR = fiber reflection probe
FDP = fiber dip probe

Almost any number possible UV = 200-800 nm
IR = 350-2500 nm
UVIR = 200-2500 nm
8 μm*
50 μm**
100 μm***
200 μm***
400 μm***
600 μm***
800 μm**
1000 μm**
in meters BX =stainless steel
ME = chrome-plated brass
MS = metall silicone

HT= high temperature
HTX= extreme high temperature
PK= PEEK
HY= Hastelloy®

*     Only for IR fibers

**   Only for UV or IR fibers

***  Only for UVIR fibers

Fiber-Optic Design

Core
Blz. 82 fiberoptic design
For spectroscopic applications, generally, multi-mode step index silica fibers are used. These range in core thickness from 50 to 1000 microns. The core is made out of pure silica. Other fiber cores with much higher absorption are made out of certain glass types or plastics. These are not offered in this catalog.
First a distinction is made between silica with high or low OH content. Silica fibers with high OH (600-1000 PPM) are used in the UV/VIS wavelength range because of the low absorption in the UV. They are referred to as UV/VIS fibers. For Deep-UV applications (below 230 nm) special solarization resistant fibers can be used.
The water content causes strong absorption peaks in the NIR wavelength range. In order to get good fibers for the NIR range, the “water” is removed from the silica. This results in low OH fibers (<2 PPM) with low absorption in the NIR. They are referred to as VIS/NIR fibers. Best of both worlds are the so-called broadband fibers, which can be used for the UV-NIR range (200-2500 nm), the product code for these fibers is UVIR. Avantes uses this broadband type of fiber as standard.


Cladding
In order to get the light guiding effect the core is cladded with a lower index of refraction material. For the highest quality fibers with the lowest absorption this is a fluorine-doped silica, the so-called silica-silica or all-silica fibers with a numerical aperture (NA) of 0.22.

Buffers
blz. 83
Without further protection fibers would easily break, because of small scratches or other irregularities on the surface. Therefore a next layer, the buffer, is added. This buffer also determines under what circumstances the fiber can be used. Temperature range, radiation, vacuum, chemical environment and bending are factors to be considered.
Polyimide buffers offer a wide temperature range (-100 to 400°C) and superior solvent resistance. Also, this material is non-flammable. Drawbacks are sensitivity to micro bending and the difficulty to remove it.
 For extreme temperatures (-270 to 700°C) metal buffers are used. Metal buffers can withstand a continuous high temperature up to 500 °C and intermittent even up to 700°C. Low outgassing makes them also excellent for use in UHV environments.

Technical Data

Fiber Material Standard
Temperature Range -190 °C to +400°C
Fiber type

Step index Mutimode

Core Numerical Aperture

0.22 ± 0.02

Buffer Polyimide
Available Diameters 50/100/200/400/600/800/1000µm
Laser damage resistant core

1,3 kW/mm2 CW at 1060 nm, up to 10 J, pulsed

Bend radius

Momentary 100 x clad radius

Long term 600 x clad radius

Transmission UV/VIS Fibers

uvfiber

Transmission VIS/NIR Fibers

irfiber

Transmission UV/VIS/NIR Fibers

pagina 101 bpi chart with line

Solarization Resistant Fibers for Deep UV applications

Most spectroscopic applications with fiber-optics have been restricted to wavelength ranges above 230 nm, because standard silica fibers with an undoped core and fluorine doped cladding are frequently damaged by exposure to deep-UV light (below 230 nm). This solarization effect is induced by the formation of “color centers” with an absorbance band of 214 nm. These color centers are formed when impurities (like Cl) exist in the core fiber material and form unbound electron pairs on the Si atom, which are affected by the deep-UV radiation.

Not long ago, solarization resistant fibers, which were hydrogen loaded, were developed (UVI). The disadvantage of these fibers is the limitation on smaller fiber diameters and limited lifetime, caused by the H2 outgassing from the fiber. Recently, with the availability of a modified core preform, a new fiber became available (UVM). This fiber provides long-term stability at 30-40% transmission (for 215 nm).

For this purpose, solarization resistant fibers, which were hydrogen loaded, were developed. The broadband fibers Avantes uses are Solarization Resistant. This means that these fibers provide long-term stability at 30-40% transmission (for 215 nm). Small degradation of the transmission can still take place.

First couple of hours of these fibers show a high drop in transmission (100% to 40%). In order to have a stable transmission from the start one can order the PRESOL option. When PRESOL is ordered with a fiber or probe Avantes pre-solarized the product for an 10-hrs period, to have a constant transmission of 30-40% @ 215 nm

 

Solarization normal UV400 fiber

solnormuv400

Solarization UVIR200-fiber

sol uvm100

Solarization 200 micron UVIR fiber

sol100micron uvm0

Ordering Information

PRESOL

  • Presolarization of UVIR fiber

 

Fiber-Optic Jacketing

For different applications Avantes offers different jacketing material. Standard fiber-optic cables and bifurcated cables are protected by a Kevlar reinforced polypropylene inner tubing with PVC red outer jacket. All of our standard reflection probes are protected by a flexible stainless steel jacket with interlocking profile (BX) or a chrome-plated brass outer jacket, with hooked profile (ME) for optimal strain relief with silicon or PTFE inner tubing. For waterproof and some medical applications stainless steel spiral jacketing with glassilk and gray outer silicon rubber coating can be provided. Inside this jacket silicon or PTFE inner tubing is used as well. For heavy industrial environments we advise the metal stainless steel (-BX) jacketing. It features a tensile strength of 950N. Especially for small, flexible, endoscopic probes we use a PVC rubber jacketing. Some specifics on the jacketing can be found in the following technical information.Contact us if you have any special conditions requirements.

 

Technical Data

Sleeve material

Kevlar reinforced PVC

Chrome plated brass (ME)

Stainless steel (BX)

Silicon coated stainless steel (MS)

Inner Tubing

Polypropylene

Silicon/PTFE

Silicon/PTFE

Silicon/PTFE

Outer dimensions

3.8 mm

5.0 mm

6.0 mm

5.8 mm

Min. bending radius

18 mm

18 mm

35 mm

18 mm

Temperature Range

-20°C to +65°C

-65°C to +250°C

-65°C to +250°C

-60°C to +180°C

Tensile Strength

150 N

350 N

950 N

70 N

Application

Standard

Industrial

Heavy Industrial

Waterproof IP67


Ordering Information

-MS Stainless steel spiral jacket with glassilk and gray outer silicon rubber coating
-ME Flexible chrome-plated brass outer jacket, with hooked profile
-BX Metal stainless steel jacket, with fully interlocking profile

 

 Standard

fiber cables fx

 -MS
 -ME
 -BX

Fiber-Optic Probe Properties

All Avantes fiber-optic cables and probes can be modified to customers request. Most materials we use in our fiber-optic assemblies can be replaced with others to improve specific chemical or thermal resistance or to enhance vacuum or pressure properties. Please contact our fiber design engineers with your specific request.
In the following paragraphs some of the most essential technical parameters are listed for the materials we use.

Thermal resistance
The thermal resistance of a fiber-optic assembly depends on some of the materials used:

  1. Fiber, the standard fiber design has a polyimide buffer, covering a wide thermal range –190 to 400 °C. For higher temperatures metal clad coated (to 500°C) fibers are recommended.
  2. Jacketing, the standard jacketing is PVC based and has a small temperature range (-20°C to 65°C), for higher temperatures a flexible metal jacketing (-BX/ME) with silicone inner tubing is recommended (up to 250°C) or stainless steel tubing (not flexible, to 750°C).
  3. Probe ends, connectors and ferrules are standard made of metal and have a wide temperature range. For special plastics, like PVC, PEEK and Teflon a limited temperature range is applicable.
  4. Bonding epoxy, the standard epoxy used is a heat curing bonding epoxy with a temperature range of –60°C to 175°C. The curing temperature is standard 100 °C, for high temperature ranges (order code -HT), the curing temperature is 200°C. 

Technical Data

Temperature range

Fiber

Sleeving

Probe end

Bonding

-20°C to +65°C

Standard Polyimide

Standard PVC

Standard metal/ PVC/PEEK/PTFE

Standard Epoxy

-30°C to +100°C

Standard Polyimide

Metal (-ME/-BX) or silicone (-MS)

Standard metal/ PEEK/PTFE

Standard Epoxy

-60°C to +200°C (HT)

Standard Polyimide

Metal (-ME/-BX) or silicone (-MS)

Standard metal/ PEEK/PTFE

High temperature curing epoxy


Ordering Information

-HT High temperature version (up to 200°C)


Chemical resistance

The chemical resistance of a fiber-optic assembly depends on some of the materials used:

  1. Fiber, the standard fiber design has a polyimide buffer, which normally will not be in contact with the sample; the quartz core provides good resistance against most solvents.
  2. Jacketing, the standard jacketing is PVC based and has a relative good chemical resistance. The –BX stainless steel and –ME chrome plated brass jacketing also have a good chemical resistance, but are not waterproof. The Silicone metal jacketing (-MS) is recommended for waterproof environment, biomedical applications, etc. The PEEK and PTFE jacketing have the best chemical resistance.
  3. Probe ends, connectors and ferrules are standard made of stainless steel (316) and are not very well suitable in corrosive environment. For most corrosive environments PEEK, PTFE or Hastelloy® C276 are recommended.
  4. Bonding, the standard heat-curing two- component epoxy used is resistant to water, inorganic acids and salts, alkalis and many aggressive organic solvents and most petrochemical products, and an extended range of organic and inorganic environments.


The table below gives a summary for the chemical resistance for most materials used. It has been drawn up on the basis of relevant sources in accordance with the state of the art; no claim to completeness. The data constitutes recommendations only, for which no liability can be accepted.

Please contact us if you have any doubt about the materials to use for your application.

Technical Data

Chemical environment

Fiber

Jacketing

Probe end

Epoxy

Acids weak

Standard Polyimide

±

-ME/-BX

-MS

-PEEK

-PVC

±

+

+

+

St. steel 316

PEEK

PTFE

Hastelloy® C276

-

+

+

+

+

Acids strong

Standard Polyimide

-

-ME/-BX

-MS

-PEEK

-PVC

-

±

+

±

St. steel 316

PEEK

PTFE

Hastelloy® C276

-

+

+

+

±

Bases weak

Standard Polyimide

±

-ME/-BX

-MS

-PEEK

-PVC

+

+

+

+

St. steel 316

PEEK

PTFE

Hastelloy® C276

+

+

+

+

+

Bases strong

Standard Polyimide

-

-ME/-BX

-MS

-PEEK

-PVC

+

+

+

+

St. steel 316

PEEK

PTFE

Hastelloy® C276

+

+

+

+

+

Aromatic carbons

Standard Polyimide

+

-ME/-BX

-MS

-PEEK

-PVC

+

+

+

+

St. steel 316

PEEK

PTFE

Hastelloy® C276

+

+

+

+

+

Alcohols

Standard Polyimide

±

-ME/-BX

-MS

-PEEK

-PVC

+

±

+

+

St. steel 316

PEEK

PTFE

Hastelloy® C276

+

+

+

+

+

Ketons/Ethers

Standard Polyimide

+

-ME/-BX

-MS

-PEEK

-PVC

+

-

+

-

St. steel 316

PEEK

PTFE

Hastelloy® C276

+

+

+

±

±

+ = good resistance
± = conditional resistant
- = not resistant

Ordering Information

-PK PEEK Probe material replaces Stainless Steel
-HY Hastelloy® C276 Probe material replaces Stainless Steel

Fiber-Optic Connectors

Standard SMA

 blz 88 SMA with ext fer

Standard SMA connector
We supply all of our standard fiber-optic cables, bundles and probes with SMA-905 connectors that easily fit into our complete range of spectrometers, light sources and accessories.
The SMA-905 connectors are screw-fitted and can be rotated over 360 degrees. The typical insertion loss for the connectors is 0.5 dB. The maximum filling diameter for bundles is 2.46 mm.

FC/PC connectors

blz 88 FCPC connector

FC/PC connectors
Optional FC/PC-connectors can be mounted to our fiber-optic products. The multimode FC/PC connectors have an extremely low insertion loss of < 0.2 dB. The FC/PC connector cannot rotate, always mounts into the same fixed position and therefore has a high reproducibility.

Ordering Information

-FC/PC FC/PC connector instead of standard SMA

Introduction Accessories

Introduction Accessories

To facilitate easier and more accurate measurements during an experiment, Avantes offers a wide selection of high quality accessories. From integrating spheres to cuvette holders, filter holders and fiber-optic multiplexers Avantes has you covered for your fiber-optic accessory needs.


Introduction Applications

Introduction Applications

On this section of the website we have listed some examples of the wide variety of applications Avantes spectrometers are used for. From plasma-wall-interaction to detection of explosives and from the Falkland Islands to Forest Fire detection in Portugal. Furthermore a number of measurement setups have been listed. Plasma, solar spectrum, Fluorescence and Absorbance measurements are just some of the many possibilities. But the Avantes Spectrometers can be used in many more applications.

Contact an application engineer to discuss your situation and the perfect spectroscopy solution for your needs.


Introduction OEM

Avantes as your OEM partner

Avantes has over 20 years of experience in applying spectroscopy and optical sensing technologies to enumerable environments and industries. Our partnership approach to working with Original Equipment Manufacturers (OEMs) is at the core of our success and philosophy as a business. For our OEM brochure click HERE

Working together with you

Avantes Sales Engineers follow a methodical discovery process with potential OEM customers to ensure our solution recommendation closely aligns with the needs of our customers. Upon reaching a consensus with our customers our team of engineers and support personnel works collaboratively to ensure successful integration and maximum interoperability. Avantes spectrometers, light sources and fiber optic sampling accessories provide the enabling technology for spectroscopy and material characterizations in these and many other industries:

  • Food and Beverage
  • Chemicals
  • Agriculture
  • Lighting
  • Biomedical Technologies
  • Metallurgy
  • Semiconductor/Thin Film

OEM spectrometer

AvaSpec - The OEM Spectrometer

The AvaSpec suite of instruments was designed with the rigors of OEM applications in mind. AvaSpec instruments offer superior resolution, sensivity, and electronic controls relative to comparable instruments on the market today. Avantes OEM customers are provided with a comprehensive OEM manual that details interfaces, wiring diagrams, instrument pinouts and connection information.

OEM optical bench

AvaBench Optical Bench

Avantes offers a range of high quality optical benches for OEM customers. The AvaBench-37.5, AvaBench-45, AvaBench-50, and AvaBench-75 all feature symmetrical Czerny-Turner design with a choice of fiber optic entrance connectors (SMA 905, FC/PC, ST). The AvaBench can be configured with any one of over 20 standard gratings covering 160-2500 nm and 16 detector arrays selected to meet the requirements of each application. Grating options range from a 150 line/mm grating for broadband applications through a 3600 line/mm grating for ultra-high resolution measurements. Avantes choice of detector arrays enables customer to meet the gamut of cost, sensitivity, resolution and signal to noise requirements associated with their OEM spectroscopy applications. Additional options include UV coatings, irradiance/non-linearity calibrations and detector collection lenses. For more detailed information about the Avabench, please click below.

Customization of Avantes optical bench designs is also available. Avantes optical bench technology can be integrated with customer’s proprietary or third party electronic boards, but can be best leveraged in combination with Avantes' proprietary AS5216 and ASC5216 electronics boards.

OEM electronics controllers

Electronics Controllers - AS-5216 & ASC-5216

Avantes optical benches can be controlled via our distinct electronics platforms. The AS-5216 and ASC-5216 platforms are capable of supporting all detector types and optical benches and provide superior performance and optimal configurability.

OEM software interface

Software Interface

Avantes proprietary AvaSoft operating software enables OEM customers to collect and save spectra in absorbance, reflection, transmittance, irradiance and scope modes. In addition to our base software solution, Avantes offers a variety of modular software add-ons for color measurement, thin film, process control and chemometry.

Most OEM applications prefer a more directed software solution for each application. Avantes Dynamic Linking Library (DLL) interface facilitates instrument control outside of our proprietary software. This interface contains functions that enable setting/getting hardware parameters from the spectrometers, designing functions for data acquisition, establishing communication with one, or multiple spectrometers and communication with other devices using TTL, digital, and analog input and output signals. The interface package also includes a number of sample programs developed to initiate writing an application in C++, Visual Basic, LabView, CSharp, Delphi and others. OEM customers are provided with a detailed manual on our DLL interface as well as direct software development support.

More information

For more information about Avantes OEM Solutions, please contact as . We look forward to speaking with you and assisting you with your application.


Introduction Solutions

Introduction solutions

Most of our customers have a clearly defined measurement they would like to address. Examples are color, absorbance and irradiance measurements. For these situations, Avantes has combined the best products to deliver solutions.

On these pages you will find a selection of the most popular solutions Avantes offers. Should your solution not be listed or do you need more information? Then don't hesitate to contact us!

For an overview of our bundles, featuring selected products for specific measurements, please open this PDF Brochure.