Lowering the threshold pump power of Ti,Er:LiNbO3 laser with ridge structure

Ridge structure is used to decrease the effective pump area of coaxially pumped Ti-diffused Er:LiNbO/sub 3/ waveguide laser such that the threshold pump power of the laser is significantly lowered. The normalized propagation constant, effective pump area, and coupling efficiency as functions of the ridge width and depth were calculated for waveguides with different initial Ti strip thicknesses. The results show that the reduction of the threshold pump power can be as large as about 40%, while the slope efficiency is not obviously changed.