Study On LD Pumped CW Nd:GdVO₄ All-solid-state Blue And Green Laser

Based on rate equation and thermal effect analysis of laser devices, we have a general investigation on DPSSL. The dissertation is outlined as following:1. In this paper, through level structure analysis of Nd-ions doped laser crystal, the four-level rate equation is obtained. Based on the rate equation, the general expressions of threshold pump power and slop efficiency of end-pumped DPSSL are deduced. The factors, which would influence threshold pump power and slop efficiency of DPSSL, are discussed.2. Through the investigation of nonlinear coupled wave equations, second harmonic generation ( SHG ) and the SHG efficiency by second-order nonlinear effect of nonlinear crystal are researched. Additionally, based on the photons theory, phase-matching condition and the phase-matching width are analyzed.3. Through characteristic analysis of laser device in DPSSL, thermal analysis models of the rectangle laser crystal by diode laser single end-pumped laser devices are introduced. Connected with properties of Nd:GdVO₄ crystal, the factors, which would influence temperature field distribution of laser device, are discussed. Though the experiment, the thermal effect of laser device has been observed and analyzed directly. And the research will supply a theoretical instruction for effectively solving thermal lens effect of Nd:GdVO₄ crystal and improve laser performance.4. LD pumped Nd:GdVO₄/KTP cw green laser was invented. At 19.7W end pump power, 3.68W of continuous output green laser was obtained. Considering of the loss of coupling system, the optical-optical conversion efficiency of this all-solid-state laser was 21%.5. According to cavity ring-down spectrometer technique, the precise measurement system for the high reflectivity of all-solid-state blue laser mirrors has been built. The method can accurately determine the reflectivity of a mirror at the wavelength of 946nm, using combination of linear and folded cavities. The experiments results show that the reflectivity of the concave cavity mirrors is to be 99.7943%, relative error achieves to 10^-5; and the flat mirror to be 99.7997%, relative error achieves to 10^-4. As the cavity mirror of a LD pumped Nd:YAG/BIBO laser, 220mW of continuous output at 473nm was obtained, at 3W end pump power, the optical-optical conversion efficiency of this all-solid-state laser was 7.3%. 6. LD pumped Nd:GdVO₄ quasi-three-level laser was studied, and the infrared laser was received at 912nm, which would supply a theoretical and experimental instruction for LD pumped Nd:GdVO₄ blue laser.