Novel differential measurement method of atmospheric aerosol absorption coefficient based on coaxial photo-thermal interference

A technology of atmospheric aerosol and photothermal interference, which is applied in the measurement of phase influence characteristics, etc., can solve problems such as troubles, achieve the effect of expanding dynamic range, avoiding adjustment, and improving accuracy

Inactive Publication Date: 2013-10-23
ANHUI INST OF OPTICS & FINE MECHANICS - CHINESE ACAD OF SCI
View PDF7 Cites 12 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In order to ensure the linear relationship between the phase change amount and the modulated laser power, the interference beam must be at the point of phase inversion, which is usually

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Novel differential measurement method of atmospheric aerosol absorption coefficient based on coaxial photo-thermal interference
  • Novel differential measurement method of atmospheric aerosol absorption coefficient based on coaxial photo-thermal interference
  • Novel differential measurement method of atmospheric aerosol absorption coefficient based on coaxial photo-thermal interference

Examples

Experimental program
Comparison scheme
Effect test

Embodiment

[0072]1. Armored single-mode fiber is selected as the transmission medium of the carrier laser 1, and visible light such as HeNe laser is used as the carrier to form an interference optical path through the optical fiber, and the interference light and the incident carrier laser are separated through the optical circulator 5. The reflectivity of the anti-reflection coating on the end face 6 of the light collimator is set between 26% and 30%, so that the intensity of the reflected light and the transmitted light forming interference are approximately equal;

[0073] 2. For the same atmospheric aerosol, the absorption coefficients corresponding to different wavelengths of the excitation laser 11 are different. A laser that cannot interfere with the carrier laser 11 is selected as the excitation laser. Taking into account the diameter of the excitation laser beam and the angle between the excitation laser and the interference beam, the width of the mirror on the excitation laser ...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention discloses a novel double-channel differential measurement method of an atmospheric aerosol absorption coefficient based on coaxial photo-thermal interference. The method comprises the following steps of: forming interference in a to-be-measured aerosol sample region through modulated carrier laser; designing two channel interference light paths, wherein one channel is used to detect baseline phase drift caused by gradual change of environment temperatures and platform vibration, and the other channel is used to detect the total phase change caused by excitation laser absorption of aerosol and the baseline phase drift; performing differential to obtain phase variable caused by aerosol absorption; and detecting the aerosol absorption coefficient on line on the basis of interference amplification factor calibration. The method provided by the invention can be also used for detecting the concentration of specific aerosol ingredients according to fingerprint absorption characteristics. The method provided by the invention overcomes the effect of environmental temperature change and measuring platform vibration, cancels the adjustment of phase inversion difference point, doubles the acting distance of excitation laser and detection laser and has the characteristics of convenience for operation, high detection speed, easiness for miniaturization, high detection sensitivity, and the like.

Description

Technical field: [0001] The invention relates to a new dual-channel differential measurement method using photothermal interference to detect the absorption coefficient of atmospheric aerosol. The interaction between the excitation laser and the interference beam passing through the aerosol area to be measured causes the change of the interference phase, which can be measured in real time according to the phase change The absorption coefficient of the aerosol to be measured, and monitor the evolution of the aerosol absorption coefficient over time. Selecting the excitation laser at a specific "fingerprint" wavelength enables the determination of specific aerosol trace components and their concentrations. Background technique: [0002] The radiative forcing caused by atmospheric aerosol absorption is much more complicated than that of greenhouse gases, and it is one of the most uncertain factors in the calculation of radiative forcing, which greatly affects the accuracy of at...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): G01N21/45
Inventor 邵士勇梅海平朱文越黄印博饶瑞中
Owner ANHUI INST OF OPTICS & FINE MECHANICS - CHINESE ACAD OF SCI
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products