Polarized light scattering measurement system and method based on magneto-optic modulation

Abstract

The invention relates to a polarized light scattering measurement system and method based on magneto-optic modulation. Coherent light sent out by a laser is changed to linear polarized light through a polarizer, and the linear polarized light is focused into a sample matching tank through a focusing lens. Scattered light coming out from the sample matching tank passes through an expanded beam collimating lens to reduce a divergence angle of the scattered light and collimate the diameter of an outgoing beam, and then the scattered light passes through a Faraday coil, a polarization analyzer and an expanded beam lens in sequence to obtain linear polarized light with periodic changes which can be received by a photomultiplier tube after passing through an aperture diaphragm capable of limiting a photosensitive area, signals are sent into a phase-locked amplifier by the photomultiplier tube to filter and remove external noise and white noise inside equipment, and then sent into a sampling integrator and a computer for sampling integration and digital average to obtain the particle size distribution. Compared with the prior art, the polarized light scattering measurement system and method based on the magneto-optic modulation can be used for low-intensity laser measurement without interference or damage to a sample, can be used for quickly and accurately measuring the nanoparticle size, suppressing the noise to the maximum extent and improving the measurement accuracy to enable the system to be suitable to be used in various environments.

Description

technical field [0001] The invention relates to a measurement technology, in particular to a polarized light scattering measurement system and method based on magneto-optic modulation. Background technique [0002] Light scattering technology is an important means to detect the motion properties of particles. Its main application is to quickly measure the translational diffusion coefficient of macromolecules or particles in solution, so as to determine the particle size or solubility. This method is fast and reliable, and has the advantages of not disturbing or destroying the original state of the system. And the measurement range is wide (70 nanometers - 2 microns), which can obtain accurate particle size distribution. In recent years, this technology has been involved in the particle size measurement of nanoparticles in the fields of medicine, aerospace, environment, and chemical industry, and has become an important means of characterizing ultrafine particles in dilute s...

AI Technical Summary

Problems solved by technology

[0005] The present invention aims at the problem that the current real-time measurement of light scattering requires high measurement conditions, and proposes a polarized light scattering measurement system and method based on magneto-optical modulation. The optical signal is measured through magneto-optical modulation, and then frequency-selective filtering is amplified to achieve Reduce, suppress or even eliminate noise, to suppress noise to the greatest extent, improve measurement accuracy, and adapt the system to use in various environments

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