The Study Of All-Solid-State Deep Blue Laser At 457nm

In this paper, the physical characteristics and optical properties of Nd:YVO4 laser crystal was used to analyze its 4F3/2â†'4I9/2 quasi-three-level, transition by the excitation cross section of direct-pumped Nd:YV04 crystal was analyzed, whose strongest absorption bands is the 4I11/2â†'4F3/2, and the direct-pumped Nd:YVO4 were theoretically calculated. The advantage to use the 880nm directly-pumped is that it directly excits the particle to the high laser level, which reduces the energy loss, lower the threshold and raise the slope efficiency up to a certain extent, thus the output quality of deep blue light can be greatly enhanced.By a series of theoretical analysis and experiments,6.5 W at 457 nm with M2=1.8 was obtained from a 5-mm-thick at 0.4% Nd:YVO4 laser medium and a 15-mm-long LBO nonlinear crystal in a Z-type cavity for 18.6 W absorbed pump power. An optical-to-optical efficiency with respect to the absorbed pump power was 0.35. Compared with conventional pumping, direct pumping of long wavelength can not only reduce the heat generated by the laser medium to improve the quantum efficiency, but also can significantly improve the laser output performance, increase the laser slope efficiency and reduce the threshold.