Synchronous upconversion

Abstract

The results of experiments with intracavity sum-frequency generation in a synchronously pumped Styryl-9 dye laser will be presented. An average power of 5 mW at 460 nm is generated by intracavity sum-frequency mixing of the 810 nm dye laser pulses and injected 1.06 μm pulses from a continuous wave mode-locked Nd:YAG laser. The sum frequency generation is done in a 5 mm long KTP crystal with 90° noncritical type II phase matching. The dye laser and sum-frequency tuning curves are presented. The double-pass 460 nm parametric gain is enhanced by introducing an adjustable intracavity dispersion. In parametric generation experiments outside the cavity, an 80% modulation of the double-pass sum-frequency gain is observed by using an adjustable dispersion. The reduced modulation observed intracavity is explained in terms of gain saturation and a dispersion-dependent cavity loss. The effect of the double-pass 810 nm parametric gain and loss on the pulse duration is observed, and the possibility of a parametric pulse compression and parametric mode locking is discussed.