Device which is invented based optical trapping of particles in aerosol and is used for realizing Raman spectrum detection

Abstract

The invention discloses a device which is invented based optical trapping of particles in aerosol and is used for realizing Raman spectrum detection. The device comprises two lasers, a hollow laser beam generation mechanism, an aerosol particle optical trapping mechanism, and a Raman spectrum detection mechanism; the hollow laser beam generation mechanism is used for diving laser generated by a first laser into two conical hollow laser beams; the two conical hollow laser beams are focused in an aerosol flow channel of a quartz chamber of the aerosol particle optical trapping mechanism to construct a capsule structure optical trapping trap composed of the two conical hollow laser beams, and realizing optical trapping on aerosol particles; the Raman spectrum detection mechanism is adopted for real-time spectrum detection of trapped particles. The device can be used for stable optical trapping and Raman spectrum detection of aerosol particles, eliminating fluorescence background in particle Raman signals, is rapid and nondestructive, and is capable of realizing identification of particles in aerosol.

Description

technical field [0001] The invention relates to the fields of optical tweezers, spectral analysis and microparticle detection, in particular to a device for optically trapping particles in aerosol and realizing Raman spectrum detection. Background technique [0002] Aerosol is a suspension system formed by suspending liquid or solid particles in a gas medium, in which the characteristic particle size of the particle phase is generally 1 nm to 100 μm. When the concentration of particles such as soot and infectious bacteria in the atmosphere exceeds a certain threshold, the aerosol will have a vital impact on air quality, climate change, and human health. Therefore, the detection of particles in atmospheric aerosols It has become an important part of environmental detection. [0003] The optical detection of aerosol particles can obtain the material characteristics of the particles. When combined with other features such as the shape or surface structure of the particles, mor...

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Problems solved by technology

But when the excitation light source is in the visible light band, such as 488nm, 633nm and 780nm, many biological particles (pollen, fungal spores, etc.) will have one or more fluorescent packets in a large spectral region (such as 400nm-800nm), which will The fluorescence spectrum of the particulate sample in the aerosol lacks the corresponding key spectral features, which hinders its correct identification

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