This paper reports on a Fabry-Perot interferometer arrangement acting as a beam splitter with variable reflectivity for intense CO, laser radiation up to kW cw-power.By means of the tuning of the spacing between this two plane parallel interferometer plates the intensity of the transmitted as well as the reflected part of the incident laser beam can be modulated. The properties of the interferometer in dependence on the parameters of the laser radiation and on the parameters of the interferometer plates are given in detail in the paper. Furthermore specific applications and arrangements, e.g. numerous uses in laser materials processing, the spectral diagnosis of CO2 laser radiation, the effective stabilization of the radiation power and bietable operation, which are based on the beam splitting function and the typical transmission characteristic of the Fabry-Perot interferometer as well as the principle of tuning, are discussed in the paper.
"Investigation Of A Fabry-Perot Interferometer Arrangement For Intense CO2 Laser Radiation", Proc. SPIE 1121, Interferometry '89, (3 April 1989); doi: 10.1117/12.961318; https://doi.org/10.1117/12.961318