Device and method for measuring atmospheric absorption coefficient based on phase perturbation

Abstract

The invention discloses a device and method for measuring an atmospheric absorption coefficient based on phase perturbation. The device comprises a mechanical compensation zoom system, a sample storage pipe, an optical fiber interferometer and an extinction tube, wherein the sample storage pipe also comprises a sample inlet and a sample outlet. In the invention, a relation between the phase perturbation and the atmospheric absorption coefficient is established, the effects of dispersion and absorption to the atmosphere are effectively separated, the atmospheric absorption coefficients corresponding to parallel laser beams with different wavelengths can be measured in a non-contact way while the original properties of the atmosphere are maintained, the evolution law of the atmospheric absorption coefficient along with time can be detected, and the method has the characteristics of high detection speed, high sensitivity and simple operation.

Description

technical field [0001] The invention relates to a new method for measuring the atmospheric absorption coefficient in real time, which can effectively measure the atmospheric absorption coefficient of light beams corresponding to different wavelengths, and can observe the change rule of the atmospheric absorption coefficient with time. Background technique [0002] The existence of the atmosphere directly affects the propagation of light, resulting in the attenuation of light in the atmosphere. The attenuation of light by the atmosphere is composed of two parts: scattering and absorption. Scattering changes the spatial distribution of light, and its effect is to change the radiation reaching the surface, thereby increasing the complexity of the spatial distribution of radiant energy. Absorption reduces the radiation reaching the surface on the one hand. Energy, on the other hand, the absorbed radiation energy is released immediately, heating the atmosphere, directly leading t...

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Problems solved by technology

[0006] Undoubtedly, the above method does not have real-time considerations. The particle to be measured in the state of precipitation is different from its state in the atmosphere; some of the particles are hygroscopic salts, which will change with the ambient temperature and humidity , the particles may also contain some volatile substances, which may volatilize during the collection process, and even the collected particles may undergo some chemical changes with each other, etc. In addition, the role of overlapping multiple particles cannot be estimated at present

[0007] The thermal effect of particle absorption will cause small changes in air temperature. The temperature change can be converted into an acoustic signal for detection and processing. The absorption coefficient of the atmosphere can be measured through the connection between the light-acoustic signal and particle absorption. This method generally does not require sample concentration. , which eliminates the influence of scattered light on the measurement of the absorption coefficient, and is relatively close to the actual atmosphere, but the selectivity of the spectrometer when measuring the absorption coefficient of atmospheric aerosol particles with different particle size ranges by photoacoustic method limits the method measurement accuracy

[0008] In short, the measurement of atmospheric absorption coefficient is of great significance to the study of light transmission in the atmosphere, and also plays an important role in the study of aerosol radiation climate effects and global climate change. However, the existing measurement methods are far from meeting the needs of applications. Undoubtedly, The rapid and simple measurement method of atmospheric absorption coefficient has become an urgent research topic.

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