METHOD AND APPARATUS FOR FOURIER ANALYSIS OF LIQUID LIGHT-TRANSMITTING MEDIA Russian patent published in 2022 - IPC G01J3/00 G06F17/14 G01N21/00 

FIELD: physics.

SUBSTANCE: proposed method and apparatus relate to technical physics, namely to equipment for optical control based on obtaining a spatial frequency spectrum of the tested medium using the optical Fourier transform of a laser beam that has passed through said medium, and can be used to control the optical homogeneity or identify liquid light-transmitting media, both organic and inorganic, using optical and automation means. The claimed apparatus for optical control of a liquid light-transmitting medium comprises, located consecutively along the course of the light beam and optically coupled, a coherent light source, an opto-mechanical modulator, a polariser, a collimator, an analyser, a focusing objective, an optical spatial filter, a collimating objective, a cuvette with the liquid medium, a Fourier transform objective, a spatial frequency selector installed in the focal the plane of the Fourier transform objective, a photoelectronic multiplier, from the output whereof the signal enters the input of the electronic signal processing unit, intended for isolating the first laser beam modulation frequency harmonic by the opto-mechanical modulator and converting said harmonic into a constant level signal further supplied to the input of an ADC, and the output of the ADC is connected to a computer with software, a monitor and a printer. The spatial frequency selector is made in the form of a variable diaphragm with an adjustable aperture, wherein a screen covering the zero spatial frequency and isolating optical areas of spatial frequencies of different diameters from the Fourier transform is installed in the centre of said diaphragm.

EFFECT: increase in the accuracy, reliability, sensitivity, and speed of obtaining analysis data.

2 cl, 22 dwg