Multichannel Hybrid Lock-In Amplifier for High-Resolution Broadband Raman Spectroscopy
Year: 2024
Type: conference-paper
Abstract: Raman microscopy is a non-invasive and label-free spectroscopic technique with growing applications in the analysis of molecules and biological samples. Fast imaging requires the simultaneous acquisition of multiple wavelengths of the vibrational spectrum with high resolution$(\approx 10-100ppm)$. However, the design of a readout capable of combining high resolution and fast acquisition on many channels is still an open challenge. Here, we report a dual-mode, hybrid, multichannel instrument capable of acquiring a Raman spectrum in only$16\mu s$using analog differential lock-in amplifiers implemented in a custom CMOS chip. For slower measurements, a mixed analog-digital approach can be activated to enhance the signal-to-noise ratio by more than$20dB$compared to a fully analog mode. The system can operate in parallel on 76 channels with signals modulated up to 10MHz and an optical power down to$4uW$per channel.
Authors: Giulio Gubello, Alberto D'Onofrio, Dario Polli, Giulio Cerullo, Giorgio Ferrari
Institution: Politecnico di Milano
Language: English
Subfield: Biophysics
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W4406895401