The Study of All-Solid-State Deep Blue Laser at 457nm
|School||Changchun University of Science and Technology|
|Keywords||Dark blue lasers Directly pumped M ~ 2 factor Nd: YVO4|
In this paper, Nd : YVO4 laser crystal physical characteristics and optical properties , analysis of the 4F3 / 2 → 4I9 / 2 quasi- three-level , and direct -pumped Nd : YVO4 crystal strongest absorption band 4I11 / 2 → 4F3 / 2 transitions by the excitation cross section were analyzed , while the direct pumping theoretical calculations . The advantage of using a 880nm directly pumped directly excite the particles to the upper laser level , and thus to reduce the energy loss . Lower its threshold and the slope efficiency - given the rise , dark blue so the output quality can be significantly improved . Through a series of theoretical analysis and experimental use of a compact four - mirror folded cavity 457nm Nd: YVO4 continuous laser output . Laser beam quality factor M2 = 1.8 can be absorbed power of the Z-type cavity 18.6W 457nm the power to 6.5W , wherein the Nd : YVO4 length of 5mm, the doping concentration of 0.4 at. % , The LBO nonlinear crystal length 15mm, the optical conversion efficiency of the pump power is absorbed ηoa = 0.35. Compared with conventional pumping directly pumped long wavelength not only can reduce the heat generated in the laser medium to improve the quantum efficiency , and can also significantly improve the output performance of the laser , and to improve the slope efficiency of the laser , decrease the threshold .