Tunable resonator with a mirror of variable curvature

A variable-curvature mirror, deformed by the application of a concentrated load at its center, was developed. It was established that the deflected surface was nearly spherical. This mirror was used in a search for the optimal variant of the resonator of an electric-discharge CO₂ laser. The mode composition was studied using either a germanium exit mirror or metallized mirrors with central apertures of different diameters.