Semiconductor-pumped single frequency solid body laser - where one mode is split into two polarisation directions perpendicular to each other, used for super-heterodyne interferometers

摘要

Laser (I) is claimed, in which one mode is split into two polarisation directions vertical to each, one direction can be determined in its frequency relative to the other direction of the same mode, whilst an air gap, arranged in the Brewster angle to the optical axis, is varied in its extension. Pref. one polarisation direction acts as reference frequency determined by temp. achieved by changing the lengths of an air gap which limits the Brewster surfaces of the laser crystal. The changing of the lengths of the air gap is achieved using an adhesive of high thermal expansion and good electrical conductivity by ohmic heating, the adhesive simultaneously acting to bound both crystals, or by using a piezoelectric polymer foil, e.g., PVDF; or by using a piezoceramic. USE/ADVANTAGE - (I) can be used for superheterodyne interferometers. It is compact, has low line width, and has the ability to produce to polarised beams vertical to each other.