SEMICONDUCTOR INJECTION LASERS WITH QUANTUM SIZE EFFECT TRANSPARENT WAVEGUIDING
Original Publication Date: 1986-Apr-30
Included in the Prior Art Database: 2004-Apr-04
Xerox Disclosure Journal
It is of great interest to have semiconductor lasers that possess transparent waveguides between the active region of the laser and its end mirror facets. Examples of such structures are disclosed in U.S. Patent Application Serial No. 524,623, filed August 19, 1983. Proposed here is to make the active region even thinner at regions adjacent to the mirror facets thereby making it possible to pump the laser along its entire cavity length while providing an emitting aperture for the laser that is quite large, resulting in low beam divergence in the plane perpendicular to its p-n junction. This is accomplished by using the masking techniques taught in U.S. Patent 4,448,797 to provide the structural growth, for example, shown in Figure 1, The mask geometry dimensions must be capable of providing growth rate ratios in the central region of the mask compared to outer regions of the mask underneath the rnask lip as high as 200:1.