Research On High-Power All-Solid-State Green Laser And Its Application

During to the advantages like high efficiency, long lifetime, compactness, good beam quality, diversity in wavelength and so on, laser diode-pumped solid-state lasers (LDPSSL, DPSSL, DPL) are more and more used in manufacturing, basic research, military affairs, medical treatment, laser show, etc, taking the place of many other lasers and becoming the mainstream. It is researched theoretically and experimentally in this dissertation on high-power diode-side-pumped intra-cavity frequency-doubled all-solid-state 532nm lasers. The main points are as follows:1. The inter- and intra-national development and researching focus of all-solid-state lasers, as well as the pump methods,laser medium and commonly used frequency-doubling crystals are introduced.2. With the parameters of a Hipower-100 pump module, the thermal effects of the diode-side-pumped solid-state lasers are researched and the temperature distribution is obtained. Based on the results, the thermal stress, thermal lensing effect, thermal birefringence are theoretically calculated and simulated. The methods of reducing thermal effects are introduced.3. Under the instruction of resonator stability condition, experimental studies on high-power diode-side-pumped green lasers are conducted. With a Hipower-100 pump module and plane-parallel resonator, we obtained an output 1064nm laser power of 143.9W, of which the optical-optical conversion efficiency is 39.97%. With a flat-concave cavity, A-O Q-switching and LBO intra-cavity frequency-doubling method, we obtained a highly stable average green laser output power of 50.7W, of which the optical-optical conversion efficiency is 14.7% and the instability is 0.3255%, occupying the domestic advanced level. Using a three mirror folded cavity structure and KTP frequency-doubling, a CW green laser output power of 22.7W is obtained, which is the highest internal experimental result, as far as we know. The instability is 0.88% at 22W, and the optical-optical conversion is 8.31%. We also calculated the value of its M2 factor which is about 6.46, using the knife-edge method. With two GKPM-150 modules in tandem with each other, double acousto-optic Q-switched and frequency-doubled by SKTP, we achieved an output power of 98.2W, of which the instability is less than 1% at 97W.4. The application of green laser in laser show and medical treatment is investigated. We designed laser show systems with our 20W and 40W lasers. The application of green laser in photo-selective vaporization of the prostate is introduced and a feasible scheme is proposed. We plan to develop a 120W green laser system applied in treatment of prostate hyperplasia.