Non-Absorbing Laser Mirrors
Original Publication Date: 1988-Jul-01
Included in the Prior Art Database: 2005-Feb-15
The mirrors of a high-power quantum well (QW) laser are made non-absorbing by increasing the effective bandgap in the mirror regions. This increase in bandgap is obtained by decreasing the width of the quantum well towards the mirrors. Fig. 1 is a schematic illustration of a cross-section of a laser structure with the proposed non-absorbing mirrors. The active QW layer, consisting of GaAs, is embedded between two A1GaAs cladding layers as shown. This layer sequence is grown on the structured surface of a GaAs substrate: the center portion on a (100)-plane, both mirror regions on (411)-planes. As shown in the drawing, the width of the active QW layer is reduced in the mirror regions. This is due to the fact that, at high growth temperatures, the crystal growth speed depends on the crystal plane.