Spatial heterodyne Raman spectrometer

Abstract

The invention provides a spatial heterodyne Raman spectrometer. The spatial heterodyne Raman spectrometer comprises a laser device, a collimating lens, a light filtering assembly, a beam splitter prism, a first reflector, a second reflector, a light beam turning device, a splicing grating and an imaging device, the laser device emits a laser beam to irradiate a sample and then emits a scattered beam, the scattered beam is converged by the collimating lens and filtered by the filter assembly, then enters the beam splitter prism and is divided into two beams by a beam splitting surface of the beam splitter prism, and the two parallel beams are reflected by the first reflector and the second reflector respectively and then are reflected by the laser device. After passing through the light beam turning device, the light beam enters the splicing grating to be diffracted to form Raman diffraction light, the Raman diffraction light vertically enters the beam splitter prism, and interference is performed in the beam splitter prism to form spatial heterodyne Raman interference light; and the spatial heterodyne Raman interference light is emitted from the beam splitter prism and then enters the imaging device to obtain a spatial heterodyne Raman signal. The device enables a wave band expansion mode to be simpler and more convenient, and has the advantages of wide measurement wave band range, simple optical path adjustment, compact structure and the like.

Description

technical field [0001] The invention relates to the technical field of spectral analysis instruments, in particular to a spatial heterodyne Raman spectrometer. Background technique [0002] Raman spectroscopy is a non-destructive detection method using inelastic Raman light scattering based on the characteristics of light-matter interaction. The incident laser excites the molecular system to be measured, thereby generating Raman scattered light with a frequency different from that of the incident light. By measuring the relative intensities of specific spectral components in the Raman scattering spectrum and their frequency shifts relative to the incident light, information about the molecular system under test can be obtained. [0003] Harlander et al. published the first spatial heterodyne Raman spectroscopy measurement method in 1992, using two separate gratings to generate spatial heterodyne interference, which improved the shortcomings of traditional Fourier spectromet...

AI Technical Summary

Problems solved by technology

However, two gratings are placed on the two interference arms of the spatial heterodyne measurement method, and the angle between the grating angle and the optical axis is a specific Littrow angle, and the optical paths of the two arms must be equal; so the spatial heterodyne interferometer It is very troublesome to adjust and calibrate the optical path

In addition, in traditional spatial heterodyne measurement, only one grating can be placed on the two arms, and the measurement range is small; and if the angle of the grating needs to be adjusted to expand the measurement band, the gratings on the two arms have to be readjusted and calibrated separately, which is very troublesome

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