PHASE-SENSITIVE METHOD FOR FREQUENCY STABILISATION OF LASER RADIATION AND ACOUSTOOPTIC MODULATOR FOR REALISING PHASE MODULATION OF LASER RADIATION Russian patent published in 2012 - IPC G02F1/11 H01S3/13 

FIELD: physics.

SUBSTANCE: method involves phase modulation of radiation and passing said radiation through a resonant-absorbent dispersion medium, detecting radio-frequency beats at a photodetector of the frequency modulated radiation passing through the medium, heterodyne detection of high-frequency beats on a mixer, picking up the output constant signal of the mixer and transmitting said signal as an error signal into a negative feedback circuit to the element controlling laser frequency. Phase modulation of laser radiation is performed using an acoustooptic modulator which operates only in Raman-Nath diffraction mode.

EFFECT: possibility of obtaining error signals with zero background level, with variable slope of the linear central section thereof in a wide range of modulation frequencies.

2 cl, 3 dwg