Single-lens integrated miniature Raman spectrometer with fine resolution and high étendue

This paper presents a compact Raman spectrometer built around a plano-convex spherical lens, with which an immersed grating and a cylindrical lens are coupled, offering a spectral resolution of 1 nm in the wavelength range of 885-950 nm. By folding the optical path and pre-collimating the beam in the sagittal plane, the prepared prototype accommodates fiber input with a numerical aperture of 0.37 while maintaining a compact volume of 70×20×5mm³. The experimental results confirm the spectrometer's ability to accurately analyze Raman signals, demonstrating reliable substance identification.