Highly Sensitive Imaging Spectrometer System Based on Areal Array to Linear Array Optical Fiber Probe for Biological Spectral Detection

Abstract

Noninvasive bio-molecular spectral sensing method for scattered tissue can be utilized to accurately obtain and analyze bio-molecular information. Propagation of light in biological tissues will gradually present diffusive feature and results in severe attenuation of detection light intensity and deteriorating the signal-to-noise ratio of detection system. In our work, we built a three-channel imaging spectrometer system and designed a compatible special fiber bundle probe for diffusive spectral detection. The system can synchronously collect the spectral signals from 270 fibers in the fiber bundles then convert them into electrical signal. Aiming at the aberration in the system, we also designed a corresponding data processing method to effectively realize the wavelength calibration of spectral signals. Finally, the system was applied to the nondestructive detection of human tissues and mouse with the <inline-formula> <tex-math notation="LaTeX">$15 ~ \mu \text{W}$ </tex-math></inline-formula> white light and 4.05 mw 405 nm laser. For the above extremely weak excitation light source, our system can still obtain the high signal-to-noise ratio diffusive spectra with less than 1 s integration time. Experiments were conducted to obtain spectra of back-scattering and autofluorescence of biological tissue. Experimental results show that the system has certain advantages in biological tissue scattering spectroscopy detection and autofluorescence detection.