| 摘要 |
PURPOSE:To produce the titled laser oscillating in the basic lateral mode at low threshold value but high efficiency very easily by a method wherein an inverse mesa type step is made between both side refelctor regions and the central part in the longitudinal direction of a resonator cutting off an active layer. CONSTITUTION:When an SiO2 mask 11 is provided on the surface (100) of a P-GaAs substrate 10 to be etched with Br2+Ch3OH mixed solution and a protrusion is provided in the longitudinal direction (01-1) of a resonator, an inverse mesa type step is formed around a reflector region with excellent stability and reproducibility. After removing the mask 11, a P-Al0.4Ga0.6As layer 12, an Al0.15Ga0.85As layer 13 with no additive, an N-Al0.27Ga0.73As guide layer 14, an N-Al0.4Ga0.6As layer 15 and a P-Al0.03Ga0.97As cap layer 16 are laminated flattening the surface. The active layer 13 on the protrusion is made adjoin the guide layer 14 on the recession. After covering the top surface with the SiO2 mask 11 again and etching the layers 12-16 down to the substrate 10, the etched cavity is buried with an Al0.35Ga0.65As layer 18 making a hole into a new SiO2 layer 19 for S diffusion 20 further providing the electrodes 22, 23. In such a constitution, most of the oscillated beams may go straight ahead from the central part of the active layer 13 generating large output due to the basic lateral mode oscillation at low threshold value but high efficiency to produce the laser with high reliability. |
