RESUMEN
The thermal lens effect of terbium gallium garnet (TGG) crystal in a high power single-frequency laser severely limits the output power and the beam quality of the laser. By inserting a potassium dideuterium phosphate (DKDP) slice with negative thermo-optical coefficient into the laser resonator, the harmful influence of the thermal lens effect of the TGG crystal can be effectively mitigated. Using this method, the stable range of the laser is broadened, the bistability phenomenon of the laser during the process of changing the pump power is completely eliminated, the highest output power of an all-solid-state continuous-wave intracavity-frequency-doubling single-frequency laser at 532 nm is enhanced to 30.2 W, and the beam quality of the laser is significantly improved.
RESUMEN
The thermal lens effect of the TGG crystal is investigated theoretically and experimentally. The theoretical analysis is demonstrated by the experimental measurements on a home-made frequency-doubled Nd:YVO(4) laser with single-frequency operation. In the presence of the thermal lens effect of the TGG crystal, the output power can be optimized by shortening the distance between the cavity mirrors of M(3) and M(4) (two plane-concave mirrors placed at two sides of the second-harmonic generator). Consequently, a single-frequency laser with output power of 18.7 W at 532 nm is obtained. The power stability and the beam quality M(2) are better than ±0.4% for 5 hours and 1.08, respectively. Meanwhile, we observe and discuss a bistability-like phenomenon of the laser in the cases of increasing and decreasing the incident pump power.
RESUMEN
A continuous-wave high-power single-frequency laser with dual-wavelength output at 1064 and 532 nm is presented. The dependencies of the output power on the transmission of the output coupler and the phase-matching temperature of the LiB(3)O(5) (LBO) crystal are studied. An output coupler with transmission of 19% is used, and the temperature of LBO is controlled to the optimal phase-matching temperature of 422 K; measured maximal output powers of 33.7 W at 1064 nm and of 1.13 W at 532 nm are obtained with optical-optical conversion efficiency of 45.6%. The laser can be single-frequency operated stably and mode-hop-free, and the measured frequency drift is less than 15 MHz in 1 min. The measured Mx2 and My2 for the 1064 nm laser are 1.06 and 1.09, respectively. The measured Mx2 and My2 for the 532 nm laser are 1.12 and 1.11, respectively.