Self-passivated GaAs/W mixer diode

GaAs/tungsten Schottky barrier mixer diodes have been fabricated in a self-passivated, grown guard layer configuration. These devices have exhibited 0.64 eV barrier voltages together with the ability to withstand nanosecond RF pulses in excess of 8 ergs with no resulting deterioration in noise figure performance. Such high burnout resistance properties are attributed to the absence of any significant metallurgical interaction between the GaAs and tungsten at temperatures as high as 600°C. The somewhat high noise figures exhibited by these devices are attributed to interface states, possibly arising from strain.     

Low-threshold-current-density vertical-cavity surface-emittingAlGaAs/GaAs diode lasers

The optimization of electrically pumped vertical-cavity surface emitters (VCSEs) with conductive semiconductor-stack rear reflectors and mirror-reflectivity products of 0.93 for minimum threshold current density, J_th, is presented. Devices of two different active layer thicknesses are fabricated: 3 μm, as for conventional devices, and 0.6 μm, which, according to theoretical calculations, provides J_th for lasers with a mirror reflectivity product in the 0.90-0.95 range. For structures of 0.16-μm thick active layers, J_th values as low as 10 kA/cm² are obtained, in good agreement with theory. Analysis shows that for active layer thicknesses ⩽1 μm, J_th reaches similar minimum values for double-heterostructure and multiquantum-well structure devices of the same active medium thickness. A brief discussion of thin active medium structures is presented     

GaAs/AlAs resonant-tunneling diode for subharmonic mixers

A GaAs/AlAs resonant-tunneling diode is designed for use as part of a subharmonic mixer, and its prototypes are fabricated and characterized. Its current-voltage characteristics measured at room, liquid-nitrogen, or liquid-helium temperature provide evidence for its adequate performance over the entire temperature range. Its impedance is measured against frequency up to 40 GHz, on which basis an appropriate equivalent circuit is selected for the device, and its components are quantified. The operation of a subharmonic mixer incorporating the resonant-tunneling diode is simulated for a number of values of its quantum-well width. At liquid-helium temperature, adjusting the quantum-well width is predicted to make the appropriate local-oscillator power vary from 50 μW to 15 mW, while holding the conversion loss of a subharmonic mixer below 10 dB.     

GaAs/GaAlAs diode lasers with angled pumping stripes

Operation of DH GaAs/GaAlAs stripe contact lasers with stripes oriented nonorthogonally to the cleaved end facets of the laser is described. Such lasers, with misalignment angles ofsim2deg, do not exhibit "kinking" behavior to power levels greater than 90 mW/facet, and do not exhibit relaxation oscillations under pulsed operation. Data showing the dependence of laser wavelength, spectral half-width, transverse mode structure, facet reflectivity, and output beam angle on both stripe angle and pump current level are also presented.     

The GaAs P-N-P-N laser diode

The general structure of double-heterojunction diode lasers is shown to be consistent with the required geometry of the Shockley diode or p-n-p-n switch. When the two devices are combined in a single structure, there results an extremely simple source of high optical power (>0.5-W) pulses of very short duration (<10 ns) without the need for a complex external driver. In principle, pulse triggering and repetition rate are easily controlled, suggesting that the device has potential application in pulse-coded optical communication systems.     

850-nm diode lasers based on AlGaAsP/GaAs heterostructures

Laser heterostructures with waveguides and emitter layers made of AlGaAs and AlGaAsP alloys are grown by hydride metal-organic vapor-phase epitaxy on a GaAs substrate and studied. It was shown that the heterostructure containing AlGaAsP layers has a large curvature radius in comparison with the structure consisting of AlGaAs layers. Ridge waveguide lasers with an aperture of 100 ??m are fabricated based on the AlGaAsP/GaAs laser heterostructure and studied. The internal optical loss of the lasers is 0.75 cm^?1; the characteristic parameter T ₀ = 140 K in the temperature range of 20?C70°C. The maximum optical output power per mirror reached 4.1 W; cw lasing was retained at a heat sink temperature of 120°C.     

Ultrafast GaAs microwave PIN diode

This letter describes what is believed to be the first successful realisation of GaAs PIN diodes. The vertical structure was grown on an n+ substrate by MOCVD of a 2 ?m, 1015 cm?3 unintentionally doped n? layer followed by a 0.3 ?m, 4×1019 cm?3 Zn doped p+ layer. The isolation and insertion loss of a single shunt-mounted device are typically ?27 dB and 0.7 dB, respectively. The switching speed of the device was measured to be less than 1 ns.     

GaAs/AlGaAs grating surface-emitting diode lasers on Si substrates

A monolithic grating surface-emitting, GaAs/AlGaAs, separate-confinement-heterostructure, single-quantum-well diode laser has been fabricated on a Si substrate using a single-step metalorganic chemical vapour deposition process. An output power of 30 mW has been obtained under pulsed operation with a peak emission wavelength of 885 nm.<>     

Surface-emitting GaAs light-emitting diode/laser diode withmodified coaxial transverse junction (CTJ) structure

A novel surface-emitting light-emitting diode (LED)/laser diode (LD) with a coaxial transverse junction (CTJ) structure is demonstrated by modified structures of the well and hole types with improved thermal properties. A narrow emission pattern for the LED was realised due to the CTJ structure and preliminary results for laser operation were also obtained at low temperatures     

High-performance millimetrewave GaAs Schottky-barrier flip-chip diode

Theoretical and experimental results reveal a novel flip-chip structure which allows attainment of both parasitic and internal device element values comparable with, or even superior to, the ultrasensitive whisker-contact Schottky-diode structure. Preliminary results with neither device nor choke structure matched to mixer block show LDSB<10 dB, Tmix approximately 2000 K (91 GHz, 300 K).     

A GaAs distributed IMPATT diode amplifier

Stable microwave amplification has been obtained in GaAs distributed IMPATT (DIMPATT) diodes by the use of shorter than resonant length devices and appropriate input/output port terminations. CW output powers of 2 W were achieved at 9.5 GHz with 10-dB gain.     

Inner-stripe AlGaAs/GaAs laser diode by single-step molecular beam epitaxy

A novel fabrication technique for a real refractive-index-guide inner-stripe laser by a single-step crystal growth is reported. The injected current is confined in the p-type silicon-doped GaAs region on the V-shaped groove with (111)A slopes by the crystal-orientation-dependent amphoteric nature of the silicon impurity in GaAs.     

Analysis of GaAs tunnel diode oscillators

GaAs tunnel diode oscillators are analyzed using a tenth-order power series approximation of the current-voltage characteristics of the diodes. The analysis yields significantly better agreement between measured and calculated power outputs than previous analyses which were based on a cubic approximation of the current-voltage characteristics.     

Dual-frequency GaAs/InGaP laser diode with a GaAsSb quantum well

The results of investigation of a metal-organic-vapor-phase-epitaxy-grown GaAsSb/GaAs/InGaP laser structure are presented. Steady two-band generation caused by spatially direct and indirect optical transitions is obtained. Observation of the sum frequency shows the effective intracavity mixing of modes in semiconductor lasers of such a type.     

GaAlAs／GaAs量子阱LD泵浦Nd：YAG激光器

利用分子束外延技术生长出了ＧａＡｌＡｓ／ＧａＡｓ折射率渐变分别限制单量阱材料。用该材料作出的激光二极管作泵浦源对Ｎｄ：ＹＡＧ激光器进行端面泵浦实验，在工作电流为３．３Ａ时，ＬＤ输出功率为２．７Ｗ，得到Ｎｄ：ＹＡＧ激光器的输出功率达７００ｍＷ，光－光转换效率达２０％。     

器件模拟对AlGaAs/GaAs RTD的特性分析(英文)

使用SILVACO公司的器件模拟软件ATLAS对AlGaAs/GaAs共振隧穿二极管(RTD)进行了器件模拟,得到了不同结构的RTD的I-V特性曲线。对量子阱宽度、掺杂浓度、势垒宽度和高度对RTD的I-V特性的影响进行了详细的分析。     

All-binary AlAs—GaAs laser diode

Thin layers of AlAs and GaAs, grown by molecular beam epitaxy (MBE), are used to simulate the properties of AlxGa1-xAs. These AlAs-GaAs superlattices (SL's) are used as cladding layers (instead of AlxGa1-xAs) in heterostructure lasers capable of room-temperature operation. It is thus possible to obtain laser diodes which are composed only of the binary compounds GaAs and AlAs. The all-binary lasers are compared to conventional AlxGa1-xAs-GaAs double-heterostructure (DH) lasers grown and fabricated under similar conditions.     

Sweep oscillation mode of GaAs IMPATT diode

Properties of the sweep oscillation mode of GaAs IMPATT diodes in the millimeter-wave region are studied in comparison with Si IMPATT diodes. In spite of their narrower depletion width, the GaAs diodes oscillate at lower frequencies than the Si devices. This can be explained by using the newly measured drift velocity of GaAs.     

Double heterostructure GaAs/AlGaAs thin film diode lasers on glass substrates

The epitaxial liftoff approach has been attracting increasing interest as an alternative to lattice-mismatched heteroepitaxy. A thin-film GaAs double heterostructure injection diode laser fabricated on a glass substrate by the epitaxial liftoff technique is reported. This presages the integration of the two major optical communication materials, III-V semiconductor crystals with SiO/sub 2/ glass.<>     

GaAs flipchip pin diode for millimetre-wave application

Millimetre-wave pin diodes have been developed for the first time in a flipchip structure, to achieve repeatability in the device features. GaAs flipchip pin diodes were manufactured on a semi-insulating substrate, and bondpads were located on mesas to minimise the parasitic elements. A waveguide switch with two biased diodes has shown, in the 94 GHz window, less than 1 dB of insertion loss, greater than 30 dB of isolation, and a switching time lower than 10 nS.<>