Theoretic And Experimental Research On Laser-diode Pumped Nd:YAG Red And Blue Laser

Laser-diode pumped all-solid-state laser (DPSSL), which possessesadvantages such as high efficiency, good beam quality, compact construction,long life time, is broadly used in military affairs, medicine, communication,scientific research fields. Gain media is the main factor of the laser configurationwhich decides the laser operation efficiency and performance. Nd:YAG is one ofthe most popular gain media used in DPSL because of its excellent opticalcharacteristic and high thermal conductivity. 1.3μm laser Nd:YAG radiates is inthe low lose area of SiO2 fiber, so it is propitious to fiber transmission;Q-switched 1.3μm laser has very high pulse peak value and narrow pulse width,can be used in medical treatment, distance measurement, machining, lightpolymerization, communication under water, atmosphere pollution measurementand so on. On the other hand 1.3μm as a fundamental wave, its secondfrequency doubling 660nm red laser and sum frequency mixing 440nm blue laserwill be applied in multicolor display in the future.In this paper, we studied on the spectrum characteristic of Nd:YAG , useddifferent nonlinear crystals we got 660nm red laser and 473nm blue laser, themain contents of the paper are listed as below:1. Reviewed the history and development of DPSSL;introduced the lasercrystals suitable for DPSSL and their main performances;described thecontents of this paper briefly.2. Based on the energy level of Nd:YAG, we elicited the operationconditions for continuous-wave (cw) and Q-switched 1.3μm laser intheory. In experiments, a maximum 1.28W continuous wave (cw) 1.3μmoutput power was got;when used acoustic-optical Q-switched techniquewe got 1.3μm pulse laser, its average power is 209mW, pulse width is160ns, repetition rate is 5kHz.3. From the frequency doubling theory, we analyzed the opticalcharacteristics of different nonlinear crystals. Finally, considered ourexperiment condition KTP was chose as the frequency-doubling crystal,we carried out KTPⅡ-kind phase matching experiment, obtained theaverage power of 120mW, pulse width of 80ns, repetition rate at 5kHz at660nm red laser.4. Utilized Nd:YAG as the gain media, we got cw and Q-switched 946nmlaser. The power of 946nm cw laser is 1.2W, and correspondingoptic-optic transition efficiency is 6.14%. The average power of 946nmQ-switched laser is 570mW, pulse width is 80ns, repetition rate is 20kHz.Then we using PPLT nonlinear crystal got average power at 66mW at473nm blue laser, corresponding optic-optic transition efficiency from946nm to 473nm laser is 10.1%...