High-Sensitivity High-Speed Compressive Spectrometer for Raman Imaging

Abstract

Compressive Raman is a recent framework that allows for large data compression of microspectroscopy during its measurement. Because of its inherent multiplexing architecture, it has shown imaging speeds considerably higher than conventional Raman microspectroscopy. Nevertheless, the low signal-to-noise ratio of Raman scattering still poses challenges for high-sensitivity bioimaging exploiting compressive Raman: (i) the idle solvent acts as a background noise upon imaging small biological organelles, (ii) current compressive spectrometers are lossy, precluding high-sensitivity imaging. We present inexpensive high-throughput spectrometer layouts for high-sensitivity compressive hyperspectroscopy. We exploit various modalities of compressive Raman allowing for up to 80× reduction of data storage and 2× microspectroscopy speed up at a 230 nm spatial resolution. Such achievements allowed us to chemically image subdiffraction-limited biological specimens (lipid bilayers) in a few seconds, paving the way for applications of a compressive Raman framework in cell biology and nanophotonics.