Temperature-tunable UV generation using an Alexandrite laser and PPLN waveguides

Goronwy Tawy, Noelia Palomar Davidson, Glenn Churchill, Michael J. Damzen, Peter G. R. Smith, James C. Gates, and Corin B. E. Gawith

Abstract

We present a simple and novel technique for achieving ultra-violet (UV) wavelength-tunable laser operation in the continuous-wave regime. Wavelength tunable operation in the near infrared is obtained from a compact two-mirror Alexandrite laser cavity by temperature tuning of the laser crystal. Second-harmonic-generation to the UV is then achieved at 376-379 nm and 384-386 nm by temperature tuning of a periodically-poled lithium-niobate (PPLN) waveguide. A maximum UV power of 1.3 mW from 185 mW infra-red pump throughput is obtained from a third-order PPLN Λ=6.1um grating. These results show promising potential for simple and wavelength tunable access to wavelengths at 360-400 nm.