GaAs-GaAlAs distributed-feedback diode lasers with separate optical and carrier confinement

Remarkable reduction of the threshold current density is achieved in GaAs-GaAlAs distributed-feedback diode lasers by adopting a separate-confinement heterostructure. The diodes are lased successfully at temperatures up to 340 °K under pulsed operation. The lowest threshold current density is 3 kA/cm^2 at 300 °K

Liquid phase epitaxy of GaAlAs on GaAs substrates with fine surface corrugations

Liquid phase epitaxy of GaAlAs was performed on GaAs fine surface corrugations. By optimizing the growth conditions, GaAlAs layers were grown successfully with only minimal meltback

cw operation of distributed-feedback GaAs-GaAlAs diode lasers at temperatures up to 300 K

Distributed-feedback GaAs-GaAlAs diode lasers with separate optical and carrier confinement have been successfully operated under dc bias up to room temperature. They lased in a single longitudinal mode with a threshold current density of 0.94 kA/cm^2 at 170 K and 3.5 kA/cm^2 at 300 K

GaAs GaAlAs double-heterostructure injection lasers with distributed feedback

GaAs-GaAlAs double-heterostructure distributed-feedback injection lasers are investigated at temperatures between 80 and 150 K under pulsed operation. The optical feedback for laser oscillation is provided by a corrugated interface between the p-GaAs active layer and the p-GaAlAs layer. The corrugation is made by two methods, ion milling and chemical etching, and the latter method is found to give the lower threshold. The laser oscillation occurs in a single longitudinal mode, whose wavelength is stable against the change of the excitation level. The temperature dependence of the wavelength of the distributed-feedback laser is shown to be 0.5 Å/deg, which is about 1/3 to 1/4 that of the conventional Fabry-Perot (FP) laser

GaAs[Single Bond]Ga1–xAlxAs double-heterostructure distributed-feedback diode lasers

We report laser oscillation at 80–100°K in electrically pumped GaAs[Single Bond]Ga1–xAlxAs double-heterostructure distributed-feedback diode lasers. The feedback for laser oscillation was provided by a corrugated interface between the active GaAs layer and the p-Ga1–xAlxAs layer. The lowest threshold current density was 2.5 kA/cm^2 in pulsed operation. The wavelength of laser emission was 8112 Å at 82°K with a half-width of less than 0.3 Å. The temperature dependence of the laser wavelength was found to be smaller than that of the conventional Fabry-Perot laser

Corrugated laser structures

GaAs–GaAlAs double-heterostructure injection lasers consist of several epilayers of GaAs and GaAlAs grown on a GaAs substrate. The need for cleaved end mirrors may be eliminated in these lasers by incorporating internal periodic corrugation which provide feedback. This distributed feedback relies on Bragg reflection from the periodic perturbation, and thus the lasing wavelength is directly proportional to the corrugation period. Such corrugated laser structures are compatible with the fabrication of monolithic optical circuits and seem to be most suitable as light sources for integrated optics. Our group prepared corrugated structures by ion milling or chemical etching through a photoresist mask which was generated by the interference of two laser beams. We observed laser emission from GaAs–GaAlAs double heterostructures with internal corrugation when pumped electrically at 77 °K. Theoretical considerations indicate that such lasers should have a very low threshold current and a good wavelength selectivity. Further experimental work on these devices is now in progress