Efficient and compact visible microchip laser source with periodically poled nonlinear materials

摘要

A compact, optically-pumped solid-state microchip laser device uses efficient nonlinear intracavity frequency conversion for obtaining low-cost green and blue laser sources. The laser includes a solid-state gain medium, such as Nd:YVO4, and a nonlinear crystal. The nonlinear crystal is formed of periodically poled lithium niobate or periodically poled lithium tantalate, and the crystal is either MgO-doped, ZnO-doped, or stoichiometric to ensure high reliability. The nonlinear crystal provides efficient frequency doubling to translate energy from an infrared pump laser beam into the visible wavelength range. The laser device is assembled in a package having an output aperture for the output beam and being integrated with an optical bench accommodating a laser assembly. The package encloses and provides heat sinking for the semiconductor diode pump laser, the microchip laser cavity assembly, the optical bench platform, and electrical leads.

主权项

1. A solid-state microchip laser source providing a frequency doubled visible output beam, the solid-state microchip laser comprising:
a semiconductor diode pump laser providing a pump beam at a selected wavelength; and a microchip laser cavity assembly disposed to receive the pump beam, the laser cavity assembly comprising: two mirrors, each mirror defined by a coated surface, a solid-state gain element pumped by the semiconductor diode pump laser and disposed between said two mirrors, and a bulk, periodically poled nonlinear frequency doubling crystal disposed between the two mirrors, the crystal being selected from the group consisting of: periodically poled MgO-doped LiNbO3, periodically poled MgO-doped LiTaO3, periodically poled ZnO-doped LiNbO3, periodically poled ZnO-doped LiTaO3, periodically poled stoichiometric LiNbO3, and periodically poled stoichiometric LiTaO3, wherein the microchip laser cavity assembly is formed by a monolithic bonding of the gain element and the nonlinear frequency doubling crystal, and the two mirrors are provided by the optical coatings on end surfaces of the gain element and the nonlinear frequency doubling crystal, and wherein relative directions of crystallographic axes of the gain element and the nonlinear frequency doubling crystal are selected to maximize a stable and efficient output into the frequency doubled visible beam, wherein length of the gain element, length of the nonlinear frequency doubling crystal, and the angle between the crystallographic axis of the gain element and the crystallographic axis of the nonlinear frequency doubling crystal are selected to support operation in substantially a single longitudinal mode.