High-power CW tunable solid state dye lasers: from the visible to UV

Abstract

We describe a high power CW solid-state dye laser setup. With perylene orange in PMMA as gain medium an output power up to 800 mW at 576 nm and a tuning range between 565 and 595 nm is reached. The laser output shows good long time power stability. The durability can be adjusted by variation of the pump power. A feedback loop controls the laser output. At a setpoint of e.g. 100 mW, the laser output can be provided for more than eight hours with a low noise level (RMS < 10%). The spectral width of the laser emission is less than 3 GHz and can be tuned over more than 30 nm. A circular mode-profile is achieved with M2 < 1.4 [1]. Via intra-cavity second harmonic generation more than 1 mW of 290 nm UV-radiation is achieved. As nonlinear element a 7 mm BBO (Beta-Barium Borate) crystal is used. The UV laser radiation can be tuned over 10 nm. The theoretical limit of UV output is estimated to 3.5 mW. To our knowledge we present the first tunable CW polymer UV laser. While the output stability at the fundamental wavelength is reasonably good, in the UV region a significant enhancement of the noise level is observed. In addition to this the long time stability is reduced to few minutes. The limitation is mainly given by the photo-decomposition of the organic dye molecules.