Monday, May 3, 2021
1:00 PM - 1:20 PM (EDT)
Using Optical Interference Filters to Measure Autofluorescence in Substrates and Coatings
Jeremy Grace - IDEX Health & Science

*J. Grace, S. Edlou, J. Foss, C. Hodgson, J-P Rheault, J. Rosvold, K Sieber, S. Walters, IDEX Health and Science, LLC, West Henrietta, NY
In fluorescence microscopy and related applications, fluorescence from optical elements in the system can be a limiting factor in achieving low background levels. Such “autofluorescence” is considerably weaker than the fluorescence produced by the organic dyes used in fluorescence-based analytical techniques. While spectrally detailed information of autofluorescence is desirable, such information comes at a cost of sensitivity. We present straightforward approach to making sensitive fluorescence measurements using a simple chopped laser and lock-in detection scheme. By using high-quality optical filters in the excitation and detection paths, the trade-off between spectral information and ultimate sensitivity is controlled by the choice of filter edge location and bandwidth. An initial implementation of this approach, using a 405 nm diode laser as an excitation source, achieves a sensitivity of ~1 pW optical power of detected fluorescence over a bandwidth of ~125 nm centered at 505 nm. Data from measurements on glass substrates will be presented, and challenges for evaluating autofluorescence from coatings on glass will be discussed.

Session Type
Optical Coatings