Design of reflective volume Bragg grating holographic filters for Raman low wavenumber detection

The implementation of low wavenumber Raman detection relies on high-performance optical filtering components. Reflective volume Bragg gratings exhibit excellent wavelength and angular selectivity, suitable for the narrowband, high-efficiency filtering requirements of low wavenumber Raman detection. Based on the derivation of the Kogelnik theory, an analysis of the simulated reflective VBG diffraction efficiency and bandwidth influencing factors is conducted. Finally, specific parameters are determined through the analysis to design a reflective holographic filter with a peak wavelength of 785nm and a bandwidth of 0.4nm. Raman spectra as low as 50cm-1 can be measured.