Laser diode graded index layer doping

摘要

These laser diode chips generate light parallel to the top surface and utilize gratings that diffract light out top and/or bottom surfaces. Thus they have both a long light generation region and a large output area, and can provide significantly higher power than prior art semiconductor-chip diodes. The chips utilize graded index (GRIN) layers to provide light containment in the core. Previously, such GRIN layers have not been doped. We have found that doping of a portion of the graded layers generally lowers resistance and increases efficiency of the semiconductor structure while retaining the light containment effectiveness of full-wavelength-height waveguide. Lowering resistance generally also lowers heat generation and thus increases reliability.