Solid-state Crystal Growth and Its Application to Fabricate Planar Waveguides

The effect of different factors,i.e.,annealing temperature,grain size,and dopant ion on the solid-state crystal growth（SSCG）,was studied in this work.In the SSCG process induced by heat treatment,a single crystal absorbs grains near the bonding interface,forming a robust bond.Using this method,a planar waveguide（PWG） consisting of a core layer of 12 at% Yb:YAG polycrystal（100 μm） was fabricated and cladded by two YAG single crystal layers.NoYb3+ ion diffusion was observed.The CW laser performance of the Yb:YAG PWG was investigated.A maximum power of 1.14 W with a slope efficiency of 16.09% was obtained in the plano-plano resonator,and a maximum power of 1.83 W with a slope efficiency of 9.59% was obtained in the three-mirror resonator.A tunable laser with a continuous output between 1027.5 nm and 1033.5 nm was realized.