Tunable dual frequency Tm:YAG-laser

Summary form only given. While Tm:YAG lasers with their attractive wide gain profile in the infrared are available since some time, they have so far only been operating as multi-mode devices. We demonstrate a miniaturized Tm:YAG laser emitting single transverse mode radiation tunable between 1940 nm and 2030 nm. Only two controlled longitudinal modes are emitting at frequencies separated by the free spectral range of the laser resonator of 1 GHz. Each frequency is stable to better than 1 MHz. With 700 mW of pump power at 786 nm we achieve up to 80 mW dual frequency output using a longitudinal pump geometry.