Raman spectroscopy by a detector-noise-limited birefringent wedge-based Fourier transform spectrometer.

• Birefringent wedge-based Fourier transform (FT) spectrometer for low-light measurement. • Optimized optical path and data acquisition for the uniqueness of FT spectroscopy. • Comprehensive FT Raman spectrum analysis and noise characterization. • High efficiency and accuracy advantages originating directly from the FT spectrometer system. • A stable, compact, low-cost, and customizable design with potential usage in photoelectric devices, ultrafast optics, and algorithmic data analysis. The development of the Fourier transform (FT) Raman spectrometer is limited by its inherent mechanism that FT Raman are generally less sensitive than grating-based ones in the visible and near-infrared range. However, the FT Raman spectroscopy technique has been applied to other scenarios where sensitivity is not the limiting factor. Here, a new development of the birefringent wedge-based FT spectrometer technique is reported, and the system's efficiency is demonstrated from the Raman spectra of a few common laboratory solvents in the cuvette as a test example. For low-light applications, the birefringent wedge-based system shows reinforced functionality compared to Michelson interferometer-based FT spectrometers in the aspects of 1) advantage due to higher accuracy in wavenumber, especially for locating peak positions; 2) multiplex advantage, which largely improves signal-to-noise ratio (SNR). The proposed setup features a stable, compact, and customizable design and provides an up-to-date reference to the development of FT Raman spectrometers from both scientific and engineering aspects. [ABSTRACT FROM AUTHOR]