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 pu mped Ti-diffused Er:LiNbO3 waveguide laser such that the threshold pump pow er of the laser is significantly lowered. The normalized propagation consta nt, effective pump area, and coupling efficiency as functions of the ridge width and depth were calculated for waveguides with different initial Ti st rip 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 obvio usly changed.