UV generation via periodically poled MgO:LiTaO3 circular waveguide crystal and diode-based master oscillator power amplifier

Abstract

Lasers with emission wavelengths in the near-ultraviolet (UV) spectral range have been used in many applications across various fields, and the demand for these lasers has been on the rise. For example, in medicine, near-UV light has been used for fluorophore excitation. Although laser diodes emitting in this region exist, single longitudinal mode lasers emitting at 380 nm with high optical power are limited. One of the solutions to this problem is the use of second harmonic generation by a non-linear crystal. In this work, single-longitudinal-mode laser emission at 380.5 nm with an optical power of up to 13 mW has been achieved. The emission was realized by frequency doubling using a periodically poled circular waveguide crystal of stoichiometric LiTaO3 doped with MgO (PPMgSLT) pumped by a master oscillator power amplifier with optical power up to 5 W. A distributed Bragg reflector ridge waveguide laser diode at 761 nm was used as the master oscillator and a tapered amplifier as the power amplifier.