High-throughput acousto-optic-tunable-filter-based time-resolved fluorescence spectrometer for optical biopsy.

Time-resolved fluorescence spectroscopy has been studied to perform minimally invasive optical biopsy in clinical diagnostics. A critical barrier preventing current time-resolved techniques from clinical studies is their impractically long data acquisition time. We have developed an acousto-optic-tunable-filter (AOTF)-based time-resolved fluorescence spectrometer, which is capable of near real-time data acquisition. Both first-order diffraction beams are collected in this AOTF spectrometer, which results in significantly improved overall throughput. Using standard fluorescence dyes, we have demonstrated that this spectrometer can acquire 200 nm time-resolved spectra within 4 s, while its throughput is comparable to a grating-based spectrometer.