Efficient generation of 914 nm laser with high beam quality in Nd:YVO4crystal pumped byπ-polarized 808 nm diode-laser

Efficient continuous wave (cw) 914 nm laser operating on 4 F 3/2 → 4 I 9/2 transition in Nd:YVO 4 crystal end-pumped by π-polarized 808 nm diode at room temperature is reported for the first time. The highest output power is up to 4.85 W under the incident pump power of 20.3 W. The optical-to-optical efficiency is 23.9%, and the average slope efficiency is up to 40%. The beam quality factor was measured to be M 2 = 2.27 at the output power of 4 W by the traveling knife-edge method. To our knowledge, the slope efficiency is the highest and the beam quality is the best for the 914 nm laser under the similar power level by far.