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

Abstract

Efficient continuous wave (cw) 914 nm laser operating on 4 F 3/2 → 4 I 9/2 transition in Nd:YVO4 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.

Diode-laser-pumped high efficiency continuous-wave operation at 912 nm laser in Nd:GdVO4crystal

“…( 1), π-polarized 808 nm laser can be used as the pump source to increase the efficiency further. In experiments, we inserted a po-larized disk in the coupling optics system to generated πpolarized 808 nm diode laser, as it was described in [20]. Tests show that up to 82% of the polarized pump radiation is absorbed by the crystal.…”

Spectroscopic characterization and diode-pumped 910 nm laser of Nd:LiLuF4 crystal

“…, (1) where (λ) is the absorption cross section as a func tion of wavelength for q polarization, Z l and Z u are the partition functions of the lower and upper manifolds, E zl is the zero line energy defined as the energy sepa ration between the lowest Stark levels of the upper and lower multiplets, h is the Plank constant, c is the veloc ity of light and k B is the Boltzmann constant. The val ues of Z l , Z u , and E zl can be calculated using the energy structure of the 4 F 3/2 and 4 I 9/2 multiplets presented in Fig.…”

“…During the past few years quasi-three level 4 F 3/2 4 I 9/2 laser transition near 900 nm of the Nd 3+ ion has attracted much attention [1][2][3][4][5][6]. This laser has some important applications such as water vapor dif ferential absorption lidar.…”

“…A lot of work has been done on the lasing charac teristics of Nd 3+ doped fluoride and oxide crystals such as LiYF 4 , YVO 4 , GdVO 4 and YAG [1,2,4,[6][7][8][9]. Compared with oxides, Nd 3+ doped fluoride crystals have some advantages such as high transparency in a wide wavelength range and a long upper level ( 4 F 3/2 ) lifetime for energy storage.…”

Diode-pumped high-repetition-rate acousto-optically Q-switched Nd:YVO4 laser operating at 914 nm

“…For the attractive prospect of solid state lasers around 900 nm and blue lasers by using frequency doubling technology, much attention was paid on improving the performance of continuous wave (cw) quasi three level Nd 3+ doped lasers since the first report on diode pumped 946 nm Nd:YAG laser by Fan and Byer in 1987 [1][2][3][4][5][6][7][8][9][10][11][12]. Considering the application in remote sensing, pulsed 900 nm lasers will be extremely useful, especially high repetition rate oper ation with a high peak power is in demand for improving the speed and distance in transmission.…”