Integrated semiconductor diode laser pumped solid state laser

Abstract

A method and apparatus for fabricating extremely robust opto-electronic devices on a monolithic support structure is provided. Incorporated into the support structure are registration structures that are used to quickly and accurately align the various components associated with the device, typically eliminating the need for manual component alignment. The registration structures are fabricated using conventional lithographic techniques, offering alignment accuracy of a micrometer or less. Utilizing the registration structures, a gain module is fabricated that is comprised of at least a pump laser, an optical element, and a solid state gain medium. The pump laser is preferably a semiconductor diode laser that pumps the edge of the gain medium, thus eliminating many of the difficulties that arise from end pumping the medium. The optical element, interposed between the pump laser and the gain medium, collimates and/or focuses the emissions from the pump laser onto the laser medium in such a manner as to optimize the efficiency of the module. The gain module may include several pump lasers, thus increasing the achieved output power. The gain module preferably projects through a cutout in a miniature optical bench. The optical bench is comprised of a material with a very low coefficient of thermal expansion, thus providing thermal stability. The surface of the optical bench is metallized, preferably in a pattern of gold pads. Optical components to be attached to the optical bench are metallized as well, thus allowing the components to be soldered into place. The optical bench is used to form various laser systems utilizing the integral gain module.