High-Speed and Low-Noise Multichannel System for Broadband Coherent Raman Imaging

Broadband coherent Raman is a non-invasive and non-destructive spectroscopic technique with growing applications in the analysis of molecules and biological compounds. This paper presents the first 32-ch modular platform for highspeed Broadband Raman Imaging, able to simultaneously acquire and process 32 wavelengths of the spectrum with a multichannel pseudo-differential lock-in structure for the compensation of the excess noise given by the laser source. The system is based on a custom integrated CMOS front-end, specifically designed for Broadband Raman applications, and a Xilinx Artix-7 FPGA for the parallel acquisition and real-time data elaboration. Experimental results show that the system is able to reach the shot noise limit and acquire a Raman image with a pixel dwell time of 100μs.