DEVICE FOR DETERMINING PARAMETERS OF FOCUSED LASER BEAM Russian patent published in 2024 - IPC G01J1/42 

FIELD: optics; electronics.

SUBSTANCE: invention relates to optoelectronics, photonics and laser technologies, specifically to optical devices for determining the position of the focal plane and the radius of the waist of focused laser beams. Device comprises elements for forming a laser mode HG₀₁, namely: a polariser for generating linearly polarized radiation, a phase converter for creating an axially symmetric distribution of polarization from linearly polarized radiation, a polariser which selects a mode with two intensity maxima and a photosensitive layer based on a PCM. Radiation formed in this way enables to create two through craters on the surface of the PCM film by ablation, through which radiation passes through the film, forming two secondary radiation sources. Interference of transmitted radiation in the far zone leads to the appearance of bands with a period determined by the distance between the craters and which enables to calculate the dimensions of the initial (unconverted) laser beam.

EFFECT: invention enables measurement of beam sizes with intensities higher than the ablation threshold of the selected PCM in compact laser systems without the risk of damaging sensors.

2 cl, 3 dwg