Cladding waveguide lasers in femtosecond laser written Nd:KGW waveguides

Abstract

Buried cladding waveguides in Nd:KGW crystals were fabricated by femtosecond laser writing at a repetition rate of 500 kHz. Excellent waveguiding performance with low insertion loss of 1.8 dB at 1.06 μm wavelength was obtained. The waveguide is also characterized by Raman spectroscopy. Under optical pump of 806 nm light, continuous-wave waveguide lasers at 1067 nm have been achieved at room temperature. Fundamental- and high-order-mode guiding and lasing were realized by varying the waveguide diameter. A 40-μm diameter waveguide generates the maximum output power 198.5 mW with a slope efficiency of 39.4%.