Ultraviolet band quasi-single pure rotation raman spectral line signal detection device

Abstract

The invention discloses an ultraviolet band quasi-single pure rotation raman spectral line signal detection device which consists of a spectral filter unit and a signal acquisition unit. Under the irradiation of ultraviolet laser with the wavelength of 354.82nm, N2 molecules and O2 molecules produce a series of discrete spectral line scattering signals. The spectral filter unit uses an ultra-narrow band filter for filterng, uses a Fabry-Perot etalon to compress sky background noise, and uses simultaneous work of double channels to extract N2 molecule anti-Stokes pure rotation raman J=8 and J=14 characteristic spectral lines and O2 molecule anti-Stokes pure rotation raman J=11 and J=19 characteristic spectral lines, and at the same time suppression greater than 6 orders of magnitude is produced on the intensity of an elastic scattering signal with the wavelength of 354.82nm. The signal acquisition unit comprises a photodetector and a data collector to realize real-time acquisition and storage of measurement data. According to the invention, the sky background noise is effectively compressed; the detection signal-to-noise ratio is greatly enhanced; and the device is suitable for a pure rotation raman laser radar for all-day detection.

Description

technical field [0001] The invention belongs to the technical field of laser atmospheric remote sensing, and in particular relates to a quasi-single pure rotation Raman spectral line signal detection device in the ultraviolet band. Background technique [0002] The laser interacts with atmospheric aerosols or atmospheric molecules, and a scattering process occurs. The scattered light includes elastic scattered light and Raman scattered light. The frequency of the elastic scattered light is the same as that of the incident laser light, and the frequency of the Raman scattered light is different from that of the incident laser light, and it is symmetrically distributed on both sides of the incident laser frequency, and the spectrum close to the elastic scattered light is pure rotational Raman scattering spectrum, in which the elastic scattered light The spectral line on the lower frequency side is the Stokes pure rotational Raman scattering spectrum, and the spectral line on t...

AI Technical Summary

Problems solved by technology

At the same time, since the current technological level of ultraviolet band filter elements cannot produce high signal intensity suppression for wavelengths near the center wavelength of 1nm, it is difficult to achieve narrow bandwidth extraction and pure rotational pull when the spectral line interval is 0.1nm. Mann spectral line and produces more than 6 orders of magnitude suppression of nearby elastic scattering signal intensity

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