Line narrowing of a Tunable high pressure CO2 laser by means of an

A model is reported to foresee, for different mirror choices, the spectral properties of a high pressure, frequency tunable, CO2 laser, operating with a non-Littrow grating mounting. The calculations show a larger frequency selectivity for not collimated plane cavities. The model is experimentally verified in a suitable high pressure laser. In particular narrowed linewidths less than 300MHz (FWHM) are obtained.