CW mode locked Nd:YVO4 laser pumped by 20-W laser diode bar |
| |
Authors: | J K Jabczyński W ?endzian J Kwiatkowski |
| |
Institution: | (1) Institute of Optoelectronics, Military University of Technology, 2 Kaliskiego Str., 00-908 Warsaw, Poland |
| |
Abstract: | The efficient cw mode locking (cw-ML) regime was demonstrated in Nd:YVO4 laser by means of saturable absorber mirror (SAM). The 0.3-at.% Nd3+ doped 10-mm-long YVO4 crystal end pumped by 20-W diode module with a beam shaper was applied as a gain medium located in the close vicinity to
the rear flat mirror of the first arm of Z-type resonator of 316 cm total length with two curved mirrors of 100-cm curvature
radii. The SAM of 2%-saturable absorptance and saturation fluence of 50 μJ/cm2 was mounted at the opposite end of a resonator. The developed “dynamically stable” cavity design mitigates detrimental role
of thermal aberration in gain medium, enforcing clean perfect mode locking even for the highest pump densities. The cw-ML
pulses with 47.5 MHz repetition rate and pulse durations in the range of 15–20 ps were observed for a wide range of pump powers
and output coupler losses. In the best case, for 32% of output coupler transmission, up to 6.2 W of average power with near
35% slope efficiency was achieved. The thresholds for Q-switched ML, cw-ML regimes were 2.67 W and 6.13 W of pump power, respectively.
For the maximum pump power of 20 W we obtained 133 nJ of pulse energy with 16-ps pulse duration, resulting in a peak power
higher than 8 kW. The threshold energy density at SAM giving the QML regime was estimated to be about 30 μJ/cm2, threshold of cw-ML regime was 220 μJ/cm2. |
| |
Keywords: | diode pumped lasers mode locking SESAM |
本文献已被 SpringerLink 等数据库收录! |
|