AlGaAs inverted strip buried heterostructure lasers

Inverted strip buried heterostructure lasers have been fabricated. These lasers have threshold currents and quantum efficiencies that are comparable to those of conventional buried heterostructure lasers. The optical mode is confined by a weakly guiding strip loaded waveguide which makes possible operation in the fundamental transverse mode for larger stripe widths than is possible for conventional buried heterostructure lasers. Scattering of the laser light by irregularities in the sidewalls of the waveguide, which can be a serious problem in conventional buried heterostructure lasers, is also greatly reduced in these lasers

Narrow stripe AlGaAs lasers using double current confinement

Gain guided AlGaAs lasers in which the current is restricted to flow between two narrow stripes have been fabricated. The double current confinement configuration, which is fabricated by a selective meltback‐growth technique, enables the current injection to be restricted to a very narrow section of the active layer. These lasers exhibit very strong antiguiding and operate in many longitudinal modes, which are characteristics of narrow stripe lasers. Potential applications of the twin vertical stripe configuration include arrays of optically coupled lasers and, if a real index waveguiding mechanism can be combined with double current confinement, low threshold lasers

Large optical cavity AlGaAs buried heterostructure window lasers

Large optical cavity buried heterostructure window lasers in which only the transparent AlGaAs waveguiding layers, and not the active layer, extend to the laser mirrors have been fabricated. These lasers have threshold currents and differential quantum efficiencies comparable to those of regular large optical cavity buried heterostructure lasers in which the active region extends to the laser mirrors, however the window lasers have been operated under pulsed conditions at three times the power at which otherwise identical lasers without windows degrade by catastrophic mirror damage

Combined High Power and High Frequency Operation of InGaAsP/InP Lasers at 1.3μm

A simultaneous operation of a semiconductor laser at high power and high speed was demonstrated in a buried crescent laser on a P-InP substrate. In a cavity length of 300μm, a maximum CW power of 130mW at room temperature was obtained in a junction-up mounting configuration. A 3dB bandwidth in excess of 12GHz at an output power of 52mW was observed

AlGaAs lasers with micro-cleaved mirrors suitable for monolithic integration

A technique has been developed for cleaving the mirrors of AlGaAs lasers without cleaving the substrate. Micro-cleaving involves cleaving a suspended heterostructure cantilever by ultrasonic vibrations. Lasers with microcleaved mirrors have threshold currents and quantum efficiencies identical to those of similar devices with conventionally cleaved mirrors

Single-carrier-type dominated impact ionisation in multilayer structures

A new structure for III-V avalanche photodetectors in which multiplication is dominated by a single-carrier type is proposed. Calculations for a GaAs-AlGaAs detector are reported predicting multiplication dominated by electrons. The reason for this is that electrons are injected into GaAs multiplication layers from high-electric-field AlGaAs layers, while holes are injected into the GaAs layers from low-electric-field AlGaAs layers

InGaAsP p-i-n photodiodes for optical communication at the 1.3-µm wavelength

The preparation and properties of Cd-diffused p-n homojunction InGaAsP photodiodes designed specifically for operation at the 1.3-µm wavelength are described. At a reverse bias of 10 V, the dark current of these diodes was as low as 15 pA. The peak responsivity at 1.3-µm wavelength was 0.7 A/W. An impulse response (full width at half maximum) of 60 ps and a 3-dB bandwidth of 5.5 GHz were achieved.