Optical path structure of a volume holographic grating type spatial heterodyne Raman imaging spectrometer

Abstract

The present invention proposes an optical path structure of a volume holographic grating type spatial heterodyne Raman imaging spectrometer. The imaging spectrometer includes a stage, a first collimating lens, a first Raman filter, a first reflecting mirror, a first focusing lens, The first beam splitter, the second beam splitter, two second mirrors, two volume holographic prisms, the second Raman filter, the second collimating lens, the third mirror, the second focusing lens, and the exit pupil , field mirrors and area array detectors. The volume holographic grating type spatial heterodyne Raman spectrometer proposed by the present invention combines the advantages of the dispersion type Raman spectrometer and the Fourier transform Raman spectrometer, and uses a beam splitter to divide the optical path into two arm optical paths to obtain spatial heterodyne Raman interference light , and use spatial heterodyne interference light to obtain imaging spectral information; and use volume holographic prisms to increase the luminous flux of the system and increase the field of view of the system, the entire structure is compact, no moving parts, stable performance, and strong reliability.

Description

technical field [0001] The invention relates to the technical field of spectral analysis instruments, in particular to an optical path structure of a volume holographic grating type spatial heterodyne Raman imaging spectrometer. Background technique [0002] Raman spectroscopy is a non-destructive detection method based on the characteristics of light-matter interaction using inelastic Raman light scattering. The incident laser excites the measured molecular system, thereby generating Raman scattered light with a frequency different from that of the incident light. By measuring the relative intensity of a specific spectral component in the Raman scattering spectrum and its frequency shift relative to the incident light, the relevant information of the measured molecular system can be obtained. However, some chemical substances have similar Raman spectral features, which require high-resolution Raman spectrometers to distinguish them. According to the working principle of R...

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Problems solved by technology

The dispersive Raman spectrometer needs a very small slit to obtain high resolution, so the dispersive Raman spectrometer cannot obtain high luminous flux; the Fourier transform Raman spectrometer does not require an incident slit and can achieve high resolution High-efficiency and high-throughput characteristics, but this kind of spectrometer needs to use moving parts to obtain optical path difference; tunable filter Raman spectrometer has the advantages of no moving firmware and small size, but its resolution is low and it cannot work in the ultraviolet band

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