GaInAsP/InP DH laser on semi-insulating InP substrate with terrace structure

GaInAsP/InP DH lasers for the 1.3 ?m region were fabricated through a single LPE process on semi-insulating InP substrates with a terrace structure. The threshold current of the mounted lasers was typically 65 mA under CW operation at room temperature. Light output of 450 mW per facet was achieved at a pulsed injection current of 4.2 A.     

Temperature dependence of DC characteristics of NpN InP/GaAsSb/InP double heterojunction bipolar transistors: an analytical study

An analytic study of DC characteristics based on the drift-diffusion approach has been performed for the InP/GaAsSb DHBTs. The current transport of InP/GaAsSb/InP DHBTs has been investigated focusing the device temperature dependence. Our simulation results show that, at room temperature, the DC characteristics of the InP/GaAsSb/InP DHBTs similar to the conventional InP-based HBT using InGaAs as the base layer although a type-II energy band alignment is presented in the InP/GaAsSb HBT. However, due to different mechanisms for the electron injection from the emitter induced by the different conduction band alignments, the InP/GaAsSb HBTs may present a different temperature dependent behavior in term of device current gain as compared to the conventional InP/InGaAs HBTs. Higher current gain could be achieved by the InP/GaAsSb HBTs at elevated temperature.     

InP/InGaAsP p-type substrate and mass transported doubly buried heterostructure laser

A novel InP/InGaAsP buried heterostructure laser diode on p-type InP substrate has been developed. The laser has achieved a threshold current as low as 20 mA DC with high power output of 50 mW under CW operation in the fundamental transverse mode.     

A vertical monolithic combination of an InGaAsP/InP laser and a heterojunction bipolar transistor

A DH InGaAsP/InP mesa laser and a DH InGaAsP/InP mass-transport laser were successfully put together with an InGaAsP/InP heterojunction bipolar transistor in a vertical configuration. A laser threshold current as low as 17 mA and an output laser power of over 30 mW were achieved. Base injection current-controlled optical bistability and optical switching were demonstrated.     

InP/GaAsSb/InP double HBTs: a new alternative for InP-based DHBTs

We report on the physical operation and performance of MOCVD-grown abrupt heterojunction InP/GaAs_0.51Sb_0.49/InP double heterojunction bipolar transistors (DHBTs). In particular, the effect of the InP collector thickness on the breakdown voltage and on the current gain cutoff frequency is assessed and a f_T of 106 GHz is reported for a DHBT with a 400 Å base and a 2000 Å InP collector with a BV_CEO of 8 V. We show that InP/GaAsSb/InP DHBTs are characterized by a weak variation of f_T as a function of temperature. Finally, we also demonstrate that high maximum oscillation frequencies f_MAX>f_T can be achieved in scaled high-speed InP/GaAsSb/InP DHBTs, and provide estimates of the maximum cutoff frequencies achievable for this emergent but promising material system. Recent results on improved structures validate our performance predictions with cutoff frequencies well beyond 200 GHz     

Low threshold operation of 1.55 μm GaInAsP/InP DFB-BH LDsentirely grown by MOVPE on InP gratings

1.55 μm GaInAsP/InP DFB-BH LDs on corrugated InP substrates were fabricated by only two-stage MOVPE including burying layer growth. The 9 mA minimum threshold current was achieved with both facets cleaved, which the authors believe is the lowest among MOVPE grown DFB LDs with InP grating. Up to 20 mW maximum output power and 0.21 W/A differential quantum efficiency were also attained under single longitudinal mode operation     

High-Current-Gain InP/GaInP/GaAsSb/InP DHBTs With fT = 436 GHz

Combining a pseudomorphically strained (Ga,In)P emitter with a GaAs_0.6Sb_0.4 base effectively eliminates the emitter heterojunction type-II conduction band offset in InP/GaAsSb double heterojunction bipolar transistors (DHBTs). A peak f_T of 436 GHz at J_C = 10 mA/mum², with BV_CEO = 3.8 V, is achieved with 0.6 times 5 mum² InP/GalnP/GaAsSb DHBTs with a 75-nm InP collector. Compared to a binary InP emitter, the (Ga,In)P emitter doubles the DC current gain from 166 to 338 for otherwise identical devices. These are the highest DC current gain and cutoff frequencies to date in uniform base GaAsSb DHBTs. The gain improvement reported here will greatly facilitate device design tradeoffs that are encountered while scaling InP/GaAsSb DHBTs toward higher frequencies by allowing higher base doping levels and smaller emitter geometries.     

Design and characteristics of InGaAs/InP composite-channel HFET's

A design for composite-channel structures consisting of an InGaAs channel and an InP subchannel for use as heterostructure field-effect transistors is presented for the first time. This novel channel structure takes advantage of both the high drift velocity and low impact ionization of InP at high electric fields as well as the high electron mobility of InGaAs at low electric fields. It is shown that the doping density of the InP subchannel is the key parameter to realize the advantages of the composite channel. A very high transconductance of 1.29 S/mm and a current gain cutoff frequency of 68.7 GHz are achieved with 0.6 and 0.7 /spl mu/m gates, respectively. The average velocity of electrons in the composite channel is 2.9/spl times/10/sup 7/ cm/s. The devices have no kink phenomena in their I-V characteristics possibly due to low impact ionization in the InP subchannel.<>     

Low threshold InGaAsP/InP buried crescent laser with double current confinement structure

An InGaAsP/InP laser diode emitting at 1.3 μm with a crescent shaped active region is described. The active region is completely embedded in InP by a two-step LPE technique, and a double current confinement scheme is incorporated with two reverse biased p-n junctions at both sides of the active layer. A threshold current as low as 20 mA has been achieved in CW operation at room temperature. Fundamental transverse mode operation with linear light output-current characteristics and single longitudinal mode oscillation have been obtained.     

LPE growth of 1.3 ?m InGaAsP CW lasers on (110) InP substrates

Room temperature CW operation and threshold current densities below 1000 A/cm2 have been achieved near 1.3 ?m wavelength with InP/InGaAsP/InP DH lasers grown by liquid phase epitaxy on (110)-oriented InP substrates.     

Optical properties of Zn-diffused InP layers for the planar-type InGaAs/InP photodetectors

Zn diffusion into InP was carried out ex-situ using a new Zn diffusion technique with zinc phosphorus particles placed around InP materials as zinc source in a semi-closed chamber formed by a modified diffusion furnace.The optical characteristics of the Zn-diffused InP layer for the planar-type InGaAs/InP PIN photodetectors grown by molecular beam epitaxy (MBE) has been investigated by photoluminescence (PL) measurements.The temperature-dependent PL spectrum of Zn-diffused InP samples at different diffusion temperatures showed that band-to-acceptor transition dominates the PL emission,which indicates that Zn was commendably diffused into InP layer as the acceptor.High quality Zn-diffused InP layer with typically smooth surface was obtained at 580 ℃ for 10 min.Furthermore,more interstitial Zn atoms were activated to act as acceptors after a rapid annealing process.Based on the above Zn-diffusion technique,a 50μm planar-type InGaAs/InP PIN photodector device was fabricated and exhibited a low dark current of 7.73 pA under a reverse bias potential of-5 V and a high breakdown voltage of larger than 41 V (I ＜ 10 μA).In addition,a high responsivity of 0.81 A/W at 1.31 μm and 0.97 A/W at 1.55 μm was obtained in the developed PIN photodetector.     

InGaAsP/InP optical switches embedded with semi-insulating InPcurrent blocking layers

A carrier injection type of InGaAsP/InP optical switch is fabricated using a semi-insulating InP current blocking layer. The switching state is obtained by current injection of 180-1000 mA. The lifetime of the injection carrier is calculated to be 6.8 ns from the measurement of switching delay time. On the basis of these fundamental switching characteristics, the reduction of the operation current and the improvement of the modulation bandwidth are theoretically investigated. It is shown that the operation current as low as 3 mA will be attained for the switch with a 6° crossing angle and that high-speed operation up to 2 GHz will be achieved by increasing the doping level in the core layer. It is also shown that an optical switch with a crossing angle over 15° will be realized for this type of semiconductor switch     

1.3?m InGaAsP/InP distributed-feedback P-substrate partially inverted buried-heterostructure laser diode

A novel 1.3?m InGaAsP/lnP distributed-feedback buried-heterostructure laser diode on p-type InP substrate has been developed utilising a dopant diffusion technique. The laser has achieved a threshold current as low as 20 mA and high output power of 32 mW under CW and SLM operation.     

Room-temperature c.w. operation of InP/InGaAsP/InP double heterostructure diode lasers emitting at 1.55 ?m

Room-temperature c.w. operation has been achieved for stripe-geometry double heterostructure InP/InGaAsP/InP diode lasers emitting at 1.55 ?m. The heterostructures were grown by l.p.e. on (100) InP substrates, and stripes were defined by the conventional planar-stripe structure. The room-temperature (20°C) c.w. threshold current ?250 mA for a 6 ?m wide by 200 ?m long cavity.     

Broadly tunable InGaAsP/InP vertical-coupler filtered laser with low tuning current

A tuning range of 48 nm has been achieved with a tuning current of only 40 mA in a 1.55 mu m InGaAsP/InP multiquantum-well laser based on a grating-assisted vertical coupler intracavity filter. Using a combination of current and voltage tuning a 55 nm tuning range was demonstrated.<>     

基于InP衬底的GaAsSb/InP异质结晶体管

采用金属有机化学气相沉积生长了InP/GaAs0.5Sb0.5/InP 双异质结晶体三极管(DHBT)材料,研究了材料质量对器件性能的影响.制备的器件不但具有非常好的直流特性,而且还表现出良好的微波特性,其结果与能带理论的预言一致,DHBT集电结和发射结的电流理想因子分别为1.00和1.06,击穿电压高达15V,电流放大增益截止频率超过100GHz.     

Groove GaInAsP laser on semi-insulating InP

A new GaInAsP/InP injection laser was fabricated on semi-insulating substrates. The structure utilises a single LPE growth process on a grooved substrate to form an index guided device. Current confinement was obtained by the semi-insulating InP surrounding the GaInAsP active layer. Threshold current as low as 28 mA with 250 ?m cavity length was obtained. The light/current characteristic was linear up to five times Ith. A single longitudinal mode at 1.20 ?m up to 1.3 Ith was observed.     

Bias dependence of GaAs and InP MESFET parameters

A comparative analysis of the bias dependence of critical RF parameters in GaAs and InP metal-semiconductor field-effect transistors (MESFET's) led to the following conclusions. 1) The drain-gate feedback capacitance in GaAs MESFET's is lower than in InP MESFET's, because of a stronger tendency in GaAs to form stationary Gunn domains at the typical drain bias levels employed. 2) The drain-source output resistance in InP MESFET's is lower than in GaAs MESFET's mainly for high drain current units, a fact which is linked to a substrate related softer pinch-off behavior in InP. 3) The current-gain cutoff frequency fT, in the current saturation range of the GaAs MESFET decreases strongly with drain bias as a result of the formation of the stationary Gunn domain. In the InP MESFET, this effect is weaker. At the optimum bias, fT is only 10-20 percent higher in InP MESFET's than in GaAs ones.     

High-speed and high-power GaInAsP/InP junction field-effecttransistor with submicron gate

Depletion-mode GaInAsP/InP junction field-effect transistors have been fabricated on Fe-doped semi-insulating InP substrates using liquid-phase epitaxial growth techniques. The authors achieved transconductance of 24 mS (160 mS/mm), drain-source saturation current at an on gate bias of 486 mA/mm and current cutoff frequency of 18.8 GHz using a GaInAsP channel layer owing to the gate length reduction     

Characteristics of diffused-stripe InP/InGaAsP/InP lasers emitting around 1.55 µm

Fabrication and lasing characteristics of InGaAsP/InP lasers emitting around 1.55 μm are described. Zn-diffused stripe-geometry lasers with emission wavelengths in the1.53-1.60mum range were fabricated from InP/InGaAsP/InP DH epitaxial wafers prepared by a low temperature LPE technique. The dependence of the lasing charaeteristics on the stripe width was examined. The lowest threshold current (≃160 mA under CW operation at 27°C) was obtained for a laser with a 13 μm stripe. CW operation of the laser has been achieved at a heat-sink temperature as high as 53°C. For sufficiently narrow stripe widths (simeq6 mum), fundamental-transverse mode and single-longitudinal mode operation was obtained under CW operation. Moreover, the lasers have good high-frequency performance. The lasers showed excellent dynamic properties without waveform distortion under high-frequency (800 Mbits/s) large-signal pulse modulation. The full width at half maximum of the longitudinal mode envelope was approximately 30 Å at 800 Mbits/s.