Channel waveguide lasers in Nd:LGS crystals

Optical channel waveguides have been produced in Nd:LGS laser crystals by using ultrafast laser inscription with a depressed cladding configuration. The cross sectional shape of the cladding waveguides is circular, surrounded by low refractive index tracks, which makes the channel waveguides as three-dimensional tubular structures. Under optical pump of 810 nm light, continuous-wave waveguide lasers at 1068 nm have been achieved at room temperature, with minimum lasing threshold of 54 mW, a maximum slope efficiency of 24% and a maximum output power of 16 mW

Enhancement of UV Second-Harmonic Radiation at Nonlinear Interfaces with Discontinuous Second-order Susceptibilities

Abstract We investigate the generation of ultraviolet (UV) second-harmonic radiation at the boundary of a UV transparent crystal, which is derived from the automatic partial phase matching of the incident wave and the total internal reflection. By adhering to another UV non-transparent crystal with a larger second-order nonlinear coefficient χ (2), a nonlinear interface with large disparity in χ (2) is formed and the enhancement of UV second-harmonic radiation is observed experimentally. The intensity of enhanced second harmonic wave generated at the nonlinear interface is up to 11.6 times that at the crystal boundary. As a tunable phase-matching method, it may suggest potential applications in the UV, and even vacuum-UV region