Selective optical laser resonator system - is defined by two mirrors enclosing crystal dispersing element

摘要

The selective optical resonator is esp. for use with single frequency lasers and frequency stabilisers. The resonator has a bandwidth less than 0.01 Angstrom and is limited by two mirrors (2, 4) enclosing a partial polariser (6) a quarter wavelength element (8), and active circularly dispersing element (10) and a second quarter wavelength element (12). The partial polariser is an individual transparent material set at the Brewster incidence angle, and the dispersing element a paratellurite crystal. Rotation of the second quarter wave element tunes the resonator the spacing of the mirrors being small enough to allow only one resonance mode.