MULTI-PASS FOCUSING SYSTEM AND METHOD OF FOCUSING LASER RADIATION PROVIDING MULTIPLE PASSAGE OF LASER BEAM THROUGH MEASURING VOLUME

摘要

FIELD: physics, optics.;SUBSTANCE: system can be used in investigating properties of gaseous media, including with chemical reactions, in small volumes by scattering spectroscopy or light absorption. The system includes assemblies of optical elements capable of moving towards a focal point, each having two flat swivel mirrors in an adjustment head which provides independent inclination of each mirror in two directions, or a lens in between, which is mounted at double the focal distance on the beam path from the measuring volume. The assemblies enable to focus a reflected beam at the same point. One assembly, having a lens and a flat mirror or only a concave mirror, directs the laser beam such that it travels its entire path in the reverse direction, wherein the number of passages is equal to or greater than 4 depending on the number of installed assemblies of optical elements.;EFFECT: high strength of the useful signal and reduced optical distortion of the laser beam due to multiple passage of the laser beam through the measuring volume.;2 cl, 2 dwg