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Nanometer Semiconductor Thin Film To Achieve Nd: Yvo <sub> 4 </ Sub> Laser Single And Dual Wavelength Laser Passively Q,

Posted on:2012-07-20Degree:MasterType:Thesis
Country:ChinaCandidate:Y F WangFull Text:PDF
GTID:2218330341452043Subject:Optics
Abstract/Summary:PDF Full Text Request
Diode-pumped all-solid-state lasers (DPSSL) have more advantages than traditional lamp-pumped laser, such as high efficiency, compactness, high stability, and long lifetime. It's a new generation of solid-state laser devices. The thesis is mainly on the designing and service performance of the laser diode(LD) pumped Nd:YVO4 laser design and operating characteristics, the semiconductor films passively Q-switched, LD pumped Nd:YVO4 three-mirror compound cavity dual-wavelength laser.1. The nc-Ge/SiO2 films were prepared by radio-frequency (RF) magnetron sputtering technique and thermal annealing. The films has been tested the average diameter of nanocrystalline germanium and optical band gap. The film were used in the passive Q-switched operation of a LD pumped Nd:YVO4 1342nm laser. When pump power is 14W, the obtained average Q-switched pulse power is 54mW, a single Pulse energy of 1.62μJ, 33.3 kHz pulse repetition rate, Pulse width of 40ns and Peak power of 40.5W. The mechanism of samples as saturable absorber was analyzed, that the nc-Ge/SiO2 films defects and interface states are the main reason for passive Q-switched operation .2. Under the dual-wavelength laser oscillation threshold conditions on the two branches equal to the cavity length and the transmissivity. 1064nm/1342nm dual-wavelength laser of LD pumped three-mirror compound cavity was designed. The pulse duration and delay time of Q-switched pulse was numerically calculated from the rate equations of the semiconductor film passive Q-switched.3. The nc-Si/SiNx superlattice films was prepared by radio-frequency (RF) magnetron sputtering technique and thermal annealing. The films has been tested microstructure, optical band gap and nonlinear absorption coefficient. LD pumped Nd:YVO4 1064nm/1342nm continuous wave dual-wavelength laser has been studied in experiment. The output power of 1064nm and 1342nm laser are all 0.65W when pump power is 12W. On this basis, the nc-Si/SiNx superlattice films was used in the passive Q-switched operation of a LD pumped Nd:YVO4 1064nm/1342nm dual-wavelength laser. Obtained the 1064nm Q-switched pulse width of 20ns and the 1342nm Q-switched pulse width of 19ns. With the result of Z-scan, that the nc-Si/SiNx superlattice films two-photon saturable absorption are the main reason for passive Q-switched operation .The main innovations of this thesis:(1)The nc-Si/SiNx superlattice film was used to achieve the passively Q-switched in this dual-wavelength laser for the first time. (2)Radio-frequency(RF) magnetron sputtering and thermal annealing were used for the first time to make the nc-Ge/SiO2 films as saturable absorber, which were used in the LD pumped Nd:YVO4 passively Q-switched 1342nm laser.
Keywords/Search Tags:nc-Si/SiN_x superlattice film, nc-Ge/SiO2 films, passively Q-switched, Nd:YVO4 laser, dual-wavelength laser passively Q-switched, saturable absorber
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