High power red laser at 671nm by intracavity frequency doubling of a Nd:YVO₄ laser

This paper reports a high-power quasi-continuous wave (quasi-CW) source of red laser at 671nm obtained by intracavity frequency doubling of a double-end-pumped 1342nm Nd:YVO_4 laser, based on the nonlinear crystal LiB_3O_5(LBO) The average output power of 2.9W at 671nm was obtained at the incident pump power of 19.5W. The overall optical to optical efficiency is 14.9%. We have analyzed the influence of the optimal pump size, the optimal focal position and the reduction of the thermal effect on high output. The combination of double-end-pumping and the quasi-CW performance greatly reduces the thermal effect.