Birefringent static Fourier-transform spectrometer for flow cytometry and imaging spectroscopy

Area of Science:

• Optics and Photonics
• Spectroscopy
• Biomedical Imaging

Background:

• Fourier-transform spectroscopy (FTS) is a powerful technique for spectral analysis.
• Traditional FTS often requires scanning mechanisms, limiting speed and complexity.
• Integrating spectral analysis with existing motion in systems like flow cytometers presents a challenge.

Purpose of the Study:

• Introduce a new concept for a birefringent static Fourier-transform spectrometer.
• Enable spectral analysis in systems with inherent relative motion.
• Expand applications for spectral flow cytometry and hyperspectral imaging.

Main Methods:

• Utilized a polarization interferometer with a calcite Wollaston prism and crossed polarizers.
• Imaged biological particles or scenes onto the interferometer.
• Generated interferograms from position-dependent optical path delay caused by relative motion.
• Recorded interferograms using a flow cytometer detector or CMOS focal plane array.
• Applied Fourier-transform analysis to time-resolved interferograms to obtain spectra.

Main Results:

• Demonstrated a concept for a static Fourier-transform spectrometer.
• Successfully generated spectral data from moving samples or scenes.
• Showcased applicability to both spectral flow cytometry and hyperspectral imaging.

Conclusions:

• The proposed birefringent static Fourier-transform spectrometer offers a motion-based spectral acquisition method.
• This approach is suitable for integration into existing systems with linear motion.
• Potential applications include flow cytometry, conveyor belt analysis, and aerial/spaceborne imaging.