Researches Of Laser Diarry Side-pumped Nd:YAP Blue Laser

All-solid-state deep-blue-lasers with high power,high repeted frequence and good beam quality,is a new generation solid-stated laser device,which has been widely used in the fields of laser color display, super high-density optical data storage,marine resources exploration and underwater laser communication.In this dissertation, through theoretical reserches and experiments, a method of generating pulse deep-blue-laser by LD side-pumped Nd:YAP intracavity third harmonic was studied,the main contents as follows:1.The review of blue lasers development process,background, characteristics, application and realization presented firstly,as well as an overview of domestic and foreign LD pumped all-solid-state lasers study of the progress.The Nd:YAP crystal characteristics, energy levels, threshold power, the best penentrance rate and the elliptical Gaussian beam propagation in orthorhombic crystals were studied.2. Based on ray-tracing theory, using Matlab numerical analysis software the coupling system had been optimized. Selected the best combination of layers and nonlinear crystal,A single-component and the blue laser resonator structure were designed.3.The thermal lens effect about side-pumped Nd:YAP was studied,Nd:YAP crystal temperature distribution and thermal lens focal length were analyzed. Selecting a reasonable method about thermal lens testing the Nd:YAP crystal thermal lens focal length was test.After determining the optimal pumping diode array cooling temperature, by the use of thermal analysis software Ansys,the conclusion is drawn that the temperature distribution on the vertical b-axis cross section is on elliptical isothermal lines.4.Firstly using Nd:YAP crystal with polarization characteristics in place of Grand-Foucault prism to be electro-optical switched-Q polarizer, the good Q-switched effect was got.With an incident pump electric current of 75A, peak power of 513W,pulse duration of 180μs, frequency of 1kHz, the maximum 1341.4nm laser output single pulse peak energy is as high as 6.7mJ with pulse width of 91ns,optical-optical conversion efficiency of 20.4%. This Q-switched method can reduce the cavity losses, lower threshold,increase the laser output energy of about 20%.Experiments agreeed well with theoretical calculations.5.A V-folded cavity astigmatism compensation method was presented.The elliptical Gaussian laser beam of the orhombic medium, which is oscillating in cavity,can compensate for V-folded cavity astigmatism, so that oval spot can be turned to a round spot. A round spot of 1341.4nm and 670.7nm laser was experimentally obtained with V cavity.This compensation method can reduce the cavity lose with the well compensation effect.6.With ABCD matrix and equivalent G-parameter method, the cavity parameters of planoconcave and V-folded cavity with thermal lens was theoretically calculated. Optimized the cavity parameters with numerical analysis Matlab software, the best thermal stability parameters was got. According to the principle of phase matching, KTP nonlinear crystal which was cut to be type-Ⅱphase-matched was selected for second harmonic generation, LBO nonlinear crystal which was cut to be type-Ⅰphase-matched was selected for third harmonic generation, so the best polarization matching was obtained.7.It was experimentally demonstrated a high peak power 670.7nm red laser with 70ns pulse width,whose maximum puls output peak energy of 2.1mJ was achieved at incident pump peak power of 513W,pulse duration of 180μs and repeated frequence 1000Hz, showing an optical-to-optical conversion effence of 2.27%.At the same pumping conditions,447nm blue laser with spectral line width 1nm,power instability degree of 2.1%, a single pulse energy of 887μJ,which had not the unique blue-noise of quasi-three-level harmonic,was obtained.The pulse width of blue laser was 51ns and conversion efficiency was 0.96%.This is the report about the narrowest pulse width and the highest conversion efficiency of the deep blue 447nm laser.