A Spectral Imaging System with an Over 70dB SNR CMOS Image Sensor and Electrically Tunable 10nm FWHM Multi-Bandpass Filter

Abstract

This paper reports a spectral imaging system using a high signal to noise ratio(SNR) wide spectral response CMOS image sensor(CIS) and an electrically tunable multi-bandpass optical filter with narrow full width at half maximum(FWHM) of transmitted waveband. The developed CIS achieved 71dB SNR, 1.5×10＾7 e- FWC, 190-1100nm spectral sensitivity, with very high quantum efficiency. Also showed that the developed multi-bandpass filter can select four wavelengths: 630nm, 800nm, 960nm and 1050nm with 10nm FWHM. Using the developed spectral imaging system, a diffusion of 5mg/dl glucose into physiological saline solution was captured images under 960nm and 1050nm wavebands, at which absorptions of water molecules and glucose appear within UV to NIR waveband respectively.