Full depth remote scanning Raman spectrometer

Abstract

The invention discloses a Raman spectrometer capable of realizing full-depth far-end scanning. The Raman spectrometer comprises an illumination unit, a spatial light modulation unit and a spectrum collection unit, wherein the illumination unit is used for outputting near-infrared light to irradiate a sample; the spatial light modulation unit is located at the output end of the illumination unit and used for selecting spot size of Raman light scattered on the sample, so that Raman spectra with different depths can be output; the spectrum collection unit is located at the output end of the spatial light modulation unit and used for collecting the Raman spectra with different depths, processing data and outputting Raman spectrum electric signals with different depths. According to the provided Raman spectrometer, scanning is performed without moving a sample platform, far-end scanning can be realized, and probe design of the Raman spectrometer in endoscopic imaging is facilitated.

Description

technical field [0001] The invention relates to the fields of forensic criminal investigation and biomedicine, and more particularly, the invention relates to a Raman spectrometer for full-depth remote scanning. Background technique [0002] Raman spectrometers have important application prospects in many fields such as food detection, petroleum detection, material analysis, forensic criminal investigation, and life safety. Raman spectrometers were first used in the analysis of material components. With the advancement of technology, the emergence of microscopic imaging Raman spectrometers has broadened the application range of Raman spectrometers to the imaging field. [0003] The earliest microscopic Raman imaging spectrometer is based on point scanning. Since Raman scattering is inelastic scattering, its signal is attenuated by an order of magnitude relative to Rayleigh scattering, so the detection time of a single spectrum of Raman spectral signal is in milliseconds. Th...

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Problems solved by technology

[0003] The earliest microscopic Raman imaging spectrometer was based on the point scanning method. Since Raman scattering is an inelastic scattering, its signal is attenuated by an order of magnitude compared with Rayleigh scattering, so the detection time of a single spectrum of a Raman spectral signal is in milliseconds. Level, imaging-level Raman spectrometers need to perform point-scanning imaging on the imaging area, so obtaining a single Raman image requires adding a mechanical scanning structure in the three directions of X-Y-Z, which makes the structure of the sample detection end in the Raman imaging system complex and the mechanical size is large. Difficult to apply to in vivo imaging

[0004] The subsequently developed line-sweep Raman spectrometer replaces the microscope objective with a cylindrical mirror, and replaces the point scan with a line scan in the X-Y direction, which reduces the mechanical scanning mechanism at the sample end and simplifies the mechanical design of the sample arm. Requires a motorized translation stage for deep scanning

[0005] The space offset Raman spectrometer uses optical fiber or axicon lens to inject light into different depths of the sample, and realizes a full-depth Raman spectrum detection by setting multiple optical fiber probes in the lateral direction. The incident angle is incident into the sample, and the receiving fiber is deviated from the incident fiber by a certain lateral distance to realize the detection of Raman spectrum in a certain depth range. This method cannot detect Raman spectrum in the full depth range, and the crosstalk between the fibers causes the system relatively poor resolution

[0006] So in general, the depth scan of the current Raman spectrometer still depends on the precise control of the motor in the sample arm. In endoscopic imaging, the sample cannot move, so the depth scan can only be realized by controlling the microscope objective lens, which requires The precise control of the microscopic objective lens complicates the optical and mechanical design of the system. In addition, due to the existence of the mechanical scanning structure of the proximal scanning probe, the size of the probe increases accordingly, which is not conducive to its application in the field of endoscopic imaging. application

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