Abstract

An ultrabroadband Cr²⁺-doped ZnSe laser operates between 2 and 3 μm, and has been shown to operate as high-power tunable continuous-wave laser, tunable single-frequency source, in Q-switched and gain-switched regimes, as well as in actively and passively mode-locked regimes. The mode-locked Cr:ZnSe laser is especially interesting, because the exceptionally broad gain band of the material allows few-cycle operation in an important for various applications mid-infrared range. The first truly ultrashort-pulse femtosecond operation has been reported already three years ago [2] and utilized a SESAM with a semiconductor Bragg mirror for achieving passive modelockinh. Pulse duration could be shortened down to 80 fs usinf chirped mirrors, but output power stayed around 100 mW, limited mostly by absorption in the SESAM. Even more importantly, the pulse spectrum width was already at the limit of SESAM reflection band. In this configuration, the laser proved to be suitable for sensitive spectroscopic measurements [3].

© 2009 IEEE