ALL-OPTICAL, IN-LINE, UNPERTURBING AND PARALLEL MEASUREMENT OF LASER-BEAM INTENSITY WITH TRANSPARENT THIN-LAYERS OF LIQUID-CRYSTALS

It is demonstrated that unique properties of orientational interaction of light with liquid crystals allow for high precision all-optical me asurement of laser radiation intensity and determination of the focal spot location and its size. With that, non-absorptive character of the basic interaction phenomenon makes unperturbing measurement schemes f easible and ensures their applicability to high power beams. Large det ector area and independent operation of its spatially distinct regions can be utilized to carry out parallel measurements for many beams.