Fabrication and characterization of gain guided, index anti-guided planar waveguide Laser resonator

摘要

Gain-guided and index anti-guided waveguides hold great promise to increase laser output power while maintaining single mode operation. Although lasing in GG-IAG fibers was demonstrated, slope efficiency is poor and output power is low. This work presents the first, to the best of our knowledge, lasing characteristics of a diode-pumped GG-IAG planar waveguide in a plano-plano resonator configuration. The laser waveguide is fabricated using 1% doped Nd:YAG core with diffusion bonded TGG claddings. With continuous-wave pumping, 8.5% slope efficiency is demonstrated and an output power of 1.5W achieved, the highest power reported so far from a GG-IAG waveguide laser. Under such pumping condition, however, thermal lensing is shown to override gain guiding and mode narrowing is observed.