Study On All-solid-state Continues-wave Laser At 447nm

Because of the advantages of stable performance,miniaturization,high efficiency, long life and so on,LD pumped all-solid-state blue lasers get more and more attention and application of laser display,underwater communication,information storage,medical cosmetology and other fields.Current research on all-solid-state continuous-wave(CW) blue lasers mainly focuses on intracavity frequency doubling technique,but intracavity frequency tripling technique is seldom adopted.Therefore in this paper,intracavity frequency tripling CW blue laser has been theoretically and experimentally studied,which mainly includes the following several aspects:1.Based on phase matching condition,detailed calculation processes of phase matching parameters for sum frequency generation(SFG) in biaxial crystals were summarized,where formulas of effective nonlinear coefficients were modified appropriately.2.Advantages and disadvantages of two pumping methods were compared,as well as the laser performance for generating 1.3μm wavelength of several common laser crystals (Nd:YAG,Nd:YAP,Nd:YVO₄ and Nd:GdVO₄).The comparison results show that LD-side-pumped Nd:YAP laser is more suitable for generating CW 1341.4 nm fundamental light.3.Phase matching characteristics for the second harmonic generation(SHG) and third harmonic generation(THG) in KTP and LBO crystals were simulated according to their physicochemical and optical properties.After comparision of calculation results,LBO with type-Ⅰcritical phase matching(CPM) and KTP with type-ⅡCPM were chosen for SHG and THG,respectively.4.Thermal-insensitive Z-shaped folded cavity was designed according to cavity stability analysis.The maximum CW output power of 114 mW at 447 nm was obtained by using LBO for SHG and KTP for THG in a LD side-pumped Nd:YAP laser,and the experimental cures were shown to be in agreement with the theoretic analysis.At last, optical-optical conversion efficiency,output spectrum,light spot and power stability were analyzed in detail. 5.The summarization of this paper was given as well as some aspects which need to be improved.