Absolute wavelength locking of microchip lasers using pump-power modulation

摘要

Many applications such as spectroscopy, wavelength-division multiplexed telecommunications, or remote sensing, require wavelength stabilization of solid-state lasers. For continuous-wave (cw) lasers, wavelength stabilization schemes usually include an actuator such as a piezo-electric element that corrects the cavity length [1]. Besides, for stabilizing a pulsed laser, its cavity length is also piezo-electrically controlled in order to have one mode coinciding with a cw master laser wavelength, which is itself locked to a reference line [2]. In all these lasers, cw or Q-switched, optical pumping of the solid-state active medium induces thermo-optic effects and dilatation that are usually undesirable. But in the case of monolithic lasers, pump-induced thermal effects becomes useful because the short cavity length is significantly modified by fast pump power modulations. Here we aim at showing the wavelength servo-locking of cw or pulsed microchip solid-state lasers to molecular reference lines, by using the pump power as the only wavelength controller, without adding any external element.