High-energy wavelength tunable dual-channel Tm:YLF laser

A dual channel high energy solid state laser using intracavity volume Bragg gratings is presented. CW operation showed a maximum output power of 5.7 W with a slope efficiency of 48%. Implementation of a Cr:ZnSe saturable absorber with 80% transmission achieved q-switching regime with 160 ns long pulses and combined energy of 4 mJ. Each channel had less than 1 nm spectral width in the range between 1880 and 1908 nm. The spectral difference between the two channels was tuned from 5 to 20 nm, corresponding to 0.4 to 1.7 THz, providing an alternative method for generating narrowband terahertz radiation.