Electronic suppression of optical feedback instabilities in a solid-state laser

摘要

A stabilized solid-state laser in a thermal imaging system in which a laser diode pumps the solid-state laser and a modulator modulates the laser beam according to graphical data to be recorded in a thermally sensitive medium, as is used in the graphics industry. The solid-state laser is stabilized against relaxation oscillations induced in the laser by modulated light reflected back from the thermally sensitive medium. The light reflected from the medium is allowed to reenter the solid-state laser, but the optical output of the solid-state laser is sampled in the frequency band in which relaxation oscillations occur. The detected intensity is then used in a feedback circuit to control the intensity of the diode laser that is optically pumping the solid-state laser. Thereby, the data modulation does not cause the solid-state laser to oscillate, and neither a Faraday rotator nor use of a diffracted beam is required./!