Intracavity modulation of the output intensity of lasers by acoustooptic effects in liquid crystals

A demonstration is reported of the possibility of using the acoustooptic effects in liquid crystals for intracavity modulation of laser intensity. An acoustooptic cell with a nematic liquid crystal was used to modulate the intensity of He–Ne laser radiation at frequencies 0.1–15 kHz. A study was made of the dependence of the modulation process on the amplitude and frequency of longitudinal and shear strains excited in a liquid crystal film. It was found that the modulation effect caused by acoustically induced orientational oscillations of the liquid crystal molecules did not have a threshold.