Fluorescence Analysis

Fluorescence spectroscopy, also known as fluorometry or spectrofluorometry, is a type of electromagnetic spectroscopy that analyzes a sample’s fluorescence. It involves using a beam of light that excites the electrons in molecules of certain compounds and causes them to emit visible light, typically, but not necessarily. It is a valuable technique in many biological (chlorophyll and carotenoid), biochemical (diagnosis of malignancies), and environmental applications.

 For most fluorescence applications, the amount of fluorescent energy emitted is only 3% of the amount of excitation light energy. Fluorescent light has a lower energy (higher wavelength) than excitation energy and is usually scattered light. This means it emits energy in all directions.

For optimal performance, assuming the time-acquisition window is not limited, Avantes recommends our Sensline spectrometers for this application since they can support long integration times, often exceeding 5 seconds. Avantes recommends the AvaSpec-ULS2048XL back-thinned CCD spectrometer when a higher-speed acquisition is required. For maximal sensitivity, the top model of the SensLine, our AvaSpec-HERO spectrometer, is recommended.

Why choose Avantes for your fluorescence application?

  • High sensitivity for low fluorescent emission
  • Long integration time capabilities (exceeding 5 seconds)
  • High-speed acquisition
  • Light sources for the most challenging fluorescence applications

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Configuring a Setup

When configuring a measurement setup for fluorescence applications, preventing excitation light from entering the spectrometer is an important issue. Possible methods to accomplish this, where one does not exclude the other, include:

  • Using an AvaLight-HPLED light source for more challenging fluorescence applications.
  • Using a broadband light source such as the AvaLight-HAL-Mini for high output in combination with an (interference) band-pass or low-pass filter.
  • Making sure the optical path for excitation light and fluorescence are perpendicular. This means the excitation light will not enter the receiving fiber (using the CUV-FL-UV/VIS or the CUV-DA).
  • Use the decay time to separate excitation energy from the integration time start pulse. Use a pulsed light source to accomplish this (pulsed laser or AvaLight-XE or AvaLight-XE-HP Xenon flash light sources).


Avantes has developed a bundle, especially for fluorescence measurements. This bundle is suited for various fluorescence applications.

These are some of the products mentioned above. Contact one of our sales engineers for advice to find the perfect setup for your specific application.

Application Examples

Below are detailed application notes on various uses of fluorescence spectroscopy in different applications and industries.