A Compact Laser Raman Spectrometer Using a Blue Diode Laser and a Novel Combination Backscattering–Sidescattering Geometry

Laser Raman spectroscopy is a versatile and well-known technique to probe molecular vibrations. The aim of the study is to design and construct a compact, easy-to-use Raman spectrometer and verify its operation. A laser Raman spectrometer was constructed using a blue diode laser module operating at 402 nm, a novel and efficient combination of backscattering and sidescattering collection geometries, and a spectrometer employing an uncooled CCD (charge-coupled device). The choice of the excitation laser wavelength at 402 nm significantly improves the Raman generation efficiency compared to that for excitation lasers operating at longer wavelengths. Off-the-shelf optical components were used throughout the system. The Raman spectrometer is relatively compact and easy to operate. The operation of the Raman spectrometer was verified with well-known molecules. Raman spectra of several sample materials (both liquids and solids) were acquired and presented.