Portable Low Frequency Raman Spectrometer Based on Fliter

With the development of Raman spectroscopy, low frequency Raman detection has become increasingly important in drug analysis. In order to realize the detection of the low-frequency Raman spectral region of the pharmaceutical raw materials and make the Raman spectrometer portable, our designed a portable low-frequency Raman spectrometer based on the Raman optical probe system. We have completed the assembly of the prototype, the instrument size is about $260\mathrm{mm}\times 185\mathrm{mm}\times 60\mathrm{mm}$, with high portability. The Raman spectrometer is based on a single monochromator, using two beam splitters for laser beam alignment, combined with a single Longpass filter realized down to 25 cm−1Raman signal measurement. The system successfully detected the low-frequency Raman spectra of the pharmaceutical raw materials hydroxychloroquine sulfate and TiO2, and realized the discrimination of four crystal forms by low-frequency Raman spectroscopy of four different crystal forms of aripiprazole. The practicability of the Low Frequency Raman spectrometer was verified by drug detection.