Search

Compared to silicon substrates, III–V materials based on GaAs and/or InP are generally limited to small diameters, up to 150 mm for GaAs and 100 mm for InP, even though bulk wafers of 150 mm diameter have already been sampled. Herein, a new technology is proposed to extend the diameter of these materials by combining the Smart Cut technology, which is based on wafer bonding and layer transfer techniques, with tiling. In this unique approach, the donor substrate used in the layer transfer step is not a simple bulk wafer (limited in diameter), but a large‐diameter rebuilt wafer produced by tiling many coupons of wafers, which are cut from bulk III–V substrates of small diameter. As already established in high‐volume manufacturing schemes for silicon on insulator substrates generated through the Smart Cut process, the donor substrate can be repeatedly reclaimed and reused, allowing this approach to be economically viable. Herein, the production of an InP film of 200 mm diameter on silicon substrates is investigated and successfully demonstrated. This generic approach can be adapted to produce other large‐diameter III–V on Si substrates, including those of 300 mm diameter. [ABSTRACT FROM AUTHOR]

• Mid-wavelength infrared photodetectors based on type II InAs/GaSb superlattice structures grown on InP substrate. • Suppression of propagation of threading dislocations because of thick GaSb buffer layer and two step growth of it. • Successful fabrication of 640 × 512 format 2D arrays with 15 μm-pixel pitch. • Clear Human face image with high operability under cooled operation. We report the growth and characterization of band gap engineered mid-wavelength infrared photodiode, pBiBn, based on type-II InAs/GaSb superlattices on InP substrate. InP substrates are attractive material because they have high transmittance in the mid-wavelength infrared region and near thermal expansion coefficient to Si read-out IC (ROIC). Misfit dislocations due to lattice mismatch between GaSb and InP were successfully suppressed by thick GaSb buffer layer and two step growth of it. The photoluminescence (PL) spectrum from the absorption layers exhibits a peak wavelength of 5.01 μm at 77 K. The distinct PL peak was observed even at 120 K, indicating the excellent crystalline quality of T2SLs grown on an InP substrate. The dark current densities of 292 × 10−6 A/cm2 at 77 K and cut off wavelength of 5.15 μm at 80 K were measured, respectively. A clear image was obtained by fabricated focal plane array of 640 × 512 pixels with 15 μm pixel pitch, and NEDT and defective pixel rate was 50 mK and less than 1 % at 100 K, respectively. [ABSTRACT FROM AUTHOR]

The total-ionizing-dose (TID) response of indium gallium arsenide (InGaAs) MOSFETs with Al2O3 gate dielectrics and several channel lengths is evaluated under different biases. DC static characteristics show large negative threshold voltage Vth shifts and subthreshold stretchout (SS), indicating net positive charge trapping in the gate oxide and generation of the interface and border traps. Hysteresis and Id – Vgs measurements from cryogenic to high temperatures show the important role of defects in the Al2O3 gate dielectric to the TID response. Radiation-induced-hole trapping is attributed to oxygen vacancies in the Al2O3. The relatively large hysteresis in these devices is attributed primarily to dangling Al bonds in the near-interfacial Al2O3. Analysis of the temperature dependence of Vth and SS suggests that the rate at which electrons leave the Al2O3 during a positive-to-negative gate-bias sweep is higher than the rate at which they enter during a negative-to-positive gate-bias sweep. [ABSTRACT FROM AUTHOR]

This paper reports wafer-level backside process technology, established with the intent to ensure stable operation of InP ICs in the submillimeter wavelength band, which generally suffer from ground bounce and substrate resonance. Our process consists of thinning a 3-in InP wafer, forming dense vias with interval cooling steps, backside metallization with single-level wiring and crack-free dicing. We investigate the effects of the backside process on InP-based heterojunction bipolar transistors and high electron mobility transistors. The results show that the backside process contributes to stable operation up to the 300-GHz range without any degradation of transistor characteristics. [ABSTRACT FROM AUTHOR]

Heterophase equilibria in the AlxGayIn1– x– yAszP1 –z/InP heterosystem have been analyzed in terms of a simple solution model in the temperature range 813–1023 K. We have assessed the stability limits of AlGaInAsP solid solutions synthesized on indium phosphide substrates and investigated kinetic features of the crystallization of constant lattice parameter AlGaInAsP solid solutions on InP substrates. The crystallization rate of AlGaInAsP solid solutions on InP substrates has been shown to depend on the synthesis temperature, the molten zone composition and length, and the temperature gradient. In addition, it has been shown to decrease with increasing aluminum concentration, independent of the molten zone length, owing to the decrease in the diffusion coefficient in the liquid phase. We have obtained composition dependences of component distribution coefficients in the AlxGayIn1– x– yAszP1 –z /InP heterosystem and shown that raising the synthesis temperature leads to a reduction in KAl and KP. The effect of synthesis conditions on the structural and luminescence properties of AlGaInAsP solid solutions on InP has been examined. [ABSTRACT FROM AUTHOR]

Conduction band discontinuity (ΔEc) of MgSe/ZnCdSe heterojunctions were evaluated using n-i-n diodes consisting of an undoped i-MgSe layer sandwiched by n-doped ZnCdSe layers. The n-i-n diodes were fabricated on InP substrates by molecular beam epitaxy. Injection current density versus applied voltage (J-V) characteristics of the n-i-n diodes were measured at 77 K and room temperature. In addition, the theoretical J-V characteristics of the n-i-n diode were calculated while varying ΔEc. By fitting the theoretical data to the experimental data, ΔEc was estimated to be 1.2 eV from the result at 77 K. This value is similar to the ΔEc estimated from the literature. [ABSTRACT FROM AUTHOR]

The application of indium tin oxide (ITO) as the p-cladding layer of II-VI compound semiconductor laser diodes (LDs) on InP substrates was investigated. The waveguide analysis of the LD structures revealed that the optical confinement effect around the active layer was obviously improved by changing the p-cladding layer from the conventional MgSe/BeZnTe superlattice to ITO. For example, the estimated optical confinement factors were 0.15 and 0.27 for the conventional and ITO LD structure, respectively, when the emission wavelength was 580 nm. In addition, we investigated optimum LD structures, considering the optical and carrier confinements at the active layer. In experiments, light emitting devices with an ITO layer were fabricated on InP substrates via molecular beam epitaxy and radio-frequency (RF) magnetron sputtering. Yellow emissions at 582 nm were observed by current injections at room temperature. These results indicate that ITO is a promising p-cladding layer material for II-VI LDs on InP substrates. (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

II-VI-compound-semiconductor laser diode (LD) structures on InP substrates were investigated using device simulations and waveguide analysis. Our simulations showed that electron injection from the n-cladding into the active layer is hindered by the n-side barrier layer between the n-cladding and active layer. Consequently, holes are not injected into the active layer but instead leak to the n-side layers. It was shown that carrier injection efficiency can be improved by removing the n-barrier. On the contrary, no large differences were observed between the optical confinement factors of the LD structures with and without the n-barrier layer. In experiments, we have fabricated the LD structures with and without the n-barrier layer on InP substrates using molecular beam epitaxy. The turn-on voltage of the device without the n-barrier was smaller than that for the device with the n-barrier by about 5 V. Spontaneous orange emissions around 603 nm were observed for the devices without the n-barrier. In contrast, no emission was observed for the devices with the n-barrier. These results prove that the carrier injection into the active layer is enhanced by the removal of the n-barrier, leading to improved the device performances. (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

InGaAs high electron mobility transistors (HEMTs) on InP substrate with very good device performance have been grown by mental organic chemical vapor deposition (MOCVD). Room temperature Hall mobilities of the 2-DEG are measured to be over 8 700 cm/V-s with sheet carrier densities larger than 4.6×10 cm. Transistors with 1.0 μm gate length exhibits transconductance up to 842 mS/mm. Excellent depletion-mode operation, with a threshold voltage of −0.3 V and I of 673 mA/mm, is realized. The non-alloyed ohmic contact special resistance is as low as 1.66×10 Ω/cm, which is so far the lowest ohmic contact special resistance. The unity current gain cut off frequency ( f) and the maximum oscillation frequency ( f) are 42.7 and 61.3 GHz, respectively. These results are very encouraging toward manufacturing InP-based HEMT by MOCVD. [ABSTRACT FROM AUTHOR]

Abstract: The growth and thermal conductivity of InAs quantum dot (QD) stacks embedded in GaInAs matrix with AlAs compensating layers deposited on (113)B InP substrate are presented. The effect of the strain compensating AlAs layer is demonstrated through Atomic Force Microscopy (AFM) and X-ray diffraction structural analysis. The thermal conductivity (2.7W/mK at 300K) measured by the 3ω method reveals to be clearly reduced in comparison with a bulk InGaAs layer (5W/mK). In addition, the thermal conductivity measurements of S doped InP substrates and the SiN insulating layer used in the 3ω method in the 20–200°C range are also presented. An empirical law is proposed for the S doped InP substrate, which slightly differs from previously presented results. [Copyright &y& Elsevier]

Abstract: We investigated the crystalline structures of Ge1−xSnx heteroepitaxial layers with Sn contents greater than 20% grown on InP and Ge substrates. Considering the lattice mismatch between the Ge1−xSnx layers and the substrates, we achieved epitaxial growth of Ge1−xSnx layers with very high Sn content by suppressing the Sn precipitation; in addition, we improved upon the crystalline quality of Ge1−xSnx heteroepitaxial layers. As a result, we could successfully form a 130nm-thick Ge1−xSnx heteroepitaxial layer on an InP substrate with a Sn content as high as 27% without Sn precipitation. We also improved the crystalline quality of Ge1−xSnx layers by annealing at a temperature as low as 290°C. [Copyright &y& Elsevier]

The properties of InAs/In 0.53 Ga 0.37 As triangular quantum wells (QWs) grown on an InP/SiO 2 /Si integrated substrate by ion-slicing technology are investigated. The material structure and growth quality are characterized by the X-ray diffraction (XRD) and transmission electron microscope measurements. The photoluminescence (PL) spectra at various temperatures are also analyzed. The PL peak wavelengths red-shift from 1.94 to 2.13 μm with the increase of temperature from 12.4 to 300 K. The experimental results of the QWs on InP/SiO 2 /Si substrate are found to be comparable with the performance of the same QWs grown on an InP substrate. The results are promising for future integration of Si with InP-based optical devices for the applications of light emission in mid-infrared wavelength range. [ABSTRACT FROM AUTHOR]

The fabrication and characteristics of 1.3-μm InGaAsP strain-compensated multiquantum well (SCMQW) buried heterostructure (BH) laser diodes (LDs) grown by selective metal-organic chemical vapor epitaxy on a patterned InP substrate are demonstrated. The photoluminescence (PL) of the SCMQW active region grown on the patterned grooves has a narrow full-width at half-maximum of ∼ 47 meV. The BH LDs exhibit a threshold current of 6.8 mA, a slope efficiency of 0.45 mW/mA, and a light output power exceeding 30 mW at 80 mA and 20°C. The maximum operating temperature is 120°C with a characteristic temperature of 72 K in 20°C-80°C. The 3-dB modulation bandwidth can be extended as far as 11.4 GHz under a bias level of 40 mA, and the back-to-back tests show a clear and symmetric eye diagram at 10 Gb/s with a PRBS of 231-1 word length and a peak-to-peak voltage of 1.08 V at 85°C. The average increase in operational current is smaller than 0.84% after the 1500-h aging test. The mean time of the BH LDs operated at 85°C to fail is calculated as 9×104 h. These BH LDs satisfy the reliability requirement for strict loop environment and 10-Gb Ethernet application without special hermetic packaging. [ABSTRACT FROM PUBLISHER]

In this paper, we introduce a robust monolithic integration technique for fabricating photonic integrated circuits comprising optoelectronic devices (e.g., surface-illuminated photodetectors, waveguide quantum-well modulators, etc.) that are made of completely separate epitaxial structures and possibly reside at different locations across the wafer as necessary. Our technique is based on the combination of multiple crystal growth steps, judicious placement of epitaxial etch-stop layers, a carefully designed etch sequence, and self-planarization and passivation steps to compactly integrate optoelectronic devices. This multigrowth integration technique is broadly applicable to most III-V materials and can be exploited to fabricate sophisticated, highly integrated, multifunctional photonic integrated circuits on a single substrate. As a successful demonstration of this technique, we describe integrated photonic switches that consume only a 300 ×300 μm footprint and incorporate InGaAs photodetector mesas and InGaAsP/InP quantum-well modulator waveguides separated by 50 μm on an InP substrate. These switches perform electrically-reconfigurable optically-controlled wavelength conversion at multi-Gb/s data rates over the entire center telecommunication wavelength band. [ABSTRACT FROM PUBLISHER]

Lasing of triangular and square lattice photonic crystal, waveguides on InP substrate is investigated around the 1.5-μm wavelength by optical pumping. The lattice period of the fabricated structures is varied over a very large scale, thereby allowing a detailed exploration of the laser behaviors in the cases of micrometer width waveguides. A genuine distributed feedback (DFB) laser emission is observed in the gap for W2-3 waveguides in the ΓM direction of a triangular lattice. A different behavior is obtained for W3 waveguides in the ΓK direction of the same lattice as well as for W1 and W3 waveguides in the ΓX direction of a square lattice. The laser emission is found to occur at the Γ point of the Brillouin zone (wavevector k=0) when the emission frequency is outside the gap. The DFB-like laser emission is intrinsically single mode in this case. Plane wave calculations show that the field distributions of the two DFB components are radically different. The emitting mode is well localized in the guide core while the non-lasing mode spreads over the whole crystal. [ABSTRACT FROM PUBLISHER]

We describe the design, optimization and fabrication of side-illuminated p-i-n photodetectors, grown on InP substrate, suitable for surface hybrid integration in low-cost modules. The targeted functionalities of these photodetectors were a very high responsivity at 1.3- and 1.55-μm wavelengths and quasi-independent on the optical polarization, and had a high alignment tolerance. Moreover, in order to avoid any reliability problem, the principle of evanescent coupling was adopted. Two photodetectors were optimized, fabricated, and tested; the first was for classical cleaved fiber, and the second was for lensed fiber. Because the considered epitaxial structures were complicated to optimize, the method of the genetic algorithm was used, associated with a beam propagation method (BPM). The photodetectors are based on multimode diluted waveguides, which are promising structures in the field of optoelectronics and integrated optics. Starting from the presented comparisons between experimental and theoretical results, the interest of the design method is discussed and the complete performances of newly fabricated devices are presented. The aspect of the cutoff frequency is also considered [ABSTRACT FROM PUBLISHER]

Optical switching can be performed by using optical amplifiers combined with a passive waveguiding network. Recently, most of the effort in optical amplifier switch modules have been focused on monolithic switches in which the entire device is fabricated on an InP substrate together with the semiconductor optical amplifiers (SOA's). In this paper, we investigate the use of SOA's with passive polymer waveguides to make hybrid switches of varying sizes. The optical amplifiers serve dual purposes, gating the signal and amplifying the signal. Amplification is needed in order to offset the losses associated with the passive waveguide elements as well as the losses from component misalignments in the switch module. Our analysis finds the largest switch module size that can be made with the architecture used. We also calculate the maximum number of switch modules which can be cascaded in order to retain a bit-error rate (BER) under 10-9 [ABSTRACT FROM PUBLISHER]

A multimode waveguide p-i-n photodiode (WGPD) and a distributed baseband amplifier consisting of high-electron mobility transistors (HEMTs) were monolithically integrated on InP substrate using a stacked layer structure for both components. The multimode WGPD has a 3-dB bandwidth of 49 GHz. The distributed baseband amplifier has a 3-dB bandwidth of 47 GHz, though its 0.5-μm gate-length HEMTs have modest cutoff frequencies fT/fmax of 47/100 GHz. The receiver optoelectronic integrated circuit has a bandwidth of 46.5 GHz. It was packaged into a fiber-pig-tailed module, and the WGPD in the module has a high responsivity of 0.62 A/W for 1.55-μm wavelength. The module achieves a sensitivity of -22.7 dBm at 40 Gb/s and exhibits a clear eye-opening at 50 Gb/s [ABSTRACT FROM PUBLISHER]

We have demonstrated high-performance 1.3-μm InAsP strained-layer quantum-well lasers with Al-oxide confined inner stripe (ACIS) structure. The oxidized layers are consisted of strain-compensated AlAs-InP-AlInAs (6 nm/2 ML/3 nm) superlattice (SAS) layers and grown on InP substrate using gas-source molecular beam epitaxy (GS-MBE). For the structural optimization of the ACIS laser, the dependence of quantum efficiency, threshold current and lateral mode characteristics on the initial ridge width and the current aperture width have been investigated. A very low-threshold current of 2.0 mA, a high differential quantum efficiency of 67% and stable single lateral mode operation of over 40 mW were obtained for the optimized ACIS lasers. The excellent characteristics obtained in the ACIS lasers are attributed to both the current and the optical confinements by the Al-oxide layer. In addition, we confirmed high uniformity of the threshold current and the oxidized width. This device is very promising candidate for low-cost access networks and optical interconnects [ABSTRACT FROM PUBLISHER]

Ambipolar carrier migration is investigated for the first time by probing with submicrometer spatial resolution the photoluminescence emitted from the active region of an InAs quantum-dash laser grown on InP. Pumping the nanostructure with two wavelengths, 880 and 940 nm, helps to better understand the transport patterns and the role of the InP substrate. The migration parallel with the dash layer is studied in two directions: along the dash elongation and perpendicular to (across) the elongation. Besides an overall quenching in the presence of dashes, a 20% reduction in migration is observed for the along direction when compared to the across one [ABSTRACT FROM PUBLISHER]

We demonstrate broadband superluminescent diode at ~1.6-mum peak emission wavelength using InAs-InAlGaAs quantum-dash-in-well structure on InP substrate. The fabricated device exhibits the close-to-Gaussian emission with a bandwidth of up to 140 nm. The device produces a low spectrum ripple of 0.3dB and an integrated power of 1.7 mW with the corresponding bandwith of 110 nm measured at 20 degC under 8 kA/cm2 [ABSTRACT FROM PUBLISHER]

A widely tunable grating cavity laser based on the Rowland circle construction for a concave grating is proposed and demonstrated. The device is implemented by employing multichannel array structure in a Littman configuration and fabricated by integrating all elements in an InP substrate. Only one channel is turned on at a time, with coarse tuning realized by selecting the appropriate element in the channel array and fine tuning by controlling the beam deflection provided by dispersive element. An overall tuning range of 50 nm with a sidemode suppression ratio of more than 30 dB has been achieved for the six-channel device [ABSTRACT FROM PUBLISHER]

We report a photodiode on InP substrate with a cutoff wavelength of 2.39 μm and peak room-temperature external quantum efficiency of 43% at 2.23 μm. Type-II GaInAs-GaAsSb quantum wells lattice-matched to InP were placed in the absorption region for long wavelength absorption. The device showed a peak detectivity of 5.6×1010 cm√HzW-1 at 200 K. [ABSTRACT FROM PUBLISHER]

We designed and fabricated a first-ever pixelless optical up-conversion imaging device using wafer-fusion technology. The device consists of an In0.53Ga0.47As-InP p-i-n detector and a GaAs-AlGaAs light-emitting diode (LED), which were grown on an InP and a GaAs substrate, respectively, and wafer-bonded together. The layer structures and doping profiles of the common region linking the detector and LED were designed such that lateral carrier diffusion was successfully suppressed while effective electrical connection was well preserved. Pixelless up-conversion imaging from 1.5 to 0.87 μm was demonstrated. Moreover, an internal electrical gain of over 100 was observed for the detector part of the integrated device. The internal up-conversion quantum efficiency was measured to be ∼50% at room temperature. [ABSTRACT FROM PUBLISHER]

Self-organized InAs quantum-dot (QD) lasers emitting at 1.5 μm were grown by gas source molecular beam epitaxy on (100) InP substrates. Room temperature continuous-wave (CW) operation of QD-based buried ridge stripe lasers is reported. We investigated experimentally the relevant CW performances of as-cleaved InP-based QD lasers for telecom applications such as temperature properties (T0=56 K), infinite length threshold current density (J∞∼150 A/cm2 per QDs layer) and internal efficiency (0.37 W/A). Lasing in pulsed mode is observed for cavity length as short as 200 μm with a threshold current of about 37 mA, demonstrating the high gain of the QD's active core. In addition, the Henry parameter of these InP-based QD lasers is experimentally determined using the Hakki-Paoli method (αH∼2.2). [ABSTRACT FROM PUBLISHER]

We have developed a traveling-wave Mach-Zehnder modulator using an n-i-n heterostructure fabricated on an InP substrate. We obtained an extremely small π voltage (Vπ) of 2.2 V, even for a short signal-electrode length of 3 mm. We confirmed that the device has an impedance-matched electrode and operates at 40 Gb/s with a single-ended drive voltage of 2.3 V. [ABSTRACT FROM PUBLISHER]

A 100-channel wavelength-division-multiplexing channel selector monolithically integrated on an InP substrate is demonstrated. The selector consists of two arrayed waveguide gratings (AWGs), two semiconductor-optical-amplifier (SOA)-gate arrays, and a multimode interference coupler. The selector employs improved AWGs whose crosstalk is reduced with higher order mode filters. Successful channel selection and lossless operation for all channels are achieved. Error-free operation at 10 Gb/s and small sensitivity penalties between 1.8 and 3.3 dB are obtained. [ABSTRACT FROM PUBLISHER]

In this letter, we report low threshold 1.5-μm vertical-cavity surface-emitting lasers with epitaxial and dielectric distributed Bragg reflector (DBRs). The device consists of a lattice-matched InAlAs-InAlGaAs DBR grown on an InP substrate, an InAlGaAs quantum well active region, a metamorphic GaAs tunnel junction, and a SiO2-TiO2 dielectric DBR. The current confinement is achieved by oxidizing an AlAs metamorphic layer grown on top of the active region. Small aperture devices show a minimum threshold of 0.8 mA at room temperature in continuous-wave operation. [ABSTRACT FROM PUBLISHER]

A novel vertical-cavity surface-emitting laser structure has been fabricated with low loss and high reflectivity a-Al2O3/a-Si distributed Bragg reflectors. The active region consists of AlGaInAs multiple quantum wells and a tunnel junction and has been grown by a single-step metal-organic chemical vapor deposition. Laser emission at 1.3 μm was achieved under continuous-wave operation at room temperature. [ABSTRACT FROM PUBLISHER]

A multisection device technique is employed to carry out internal optical loss measurements in two types of InGaAs-InAlGaAs quantum-well structures. One structure consists of conventional identical-width quantum wells and the other, a broader spectral-width material, consists of multiple-width quantum wells in the active region. The temperature dependence of the internal optical losses is also investigated for both structures. [ABSTRACT FROM PUBLISHER]

The group refractive index dispersion in ultra-broad-band quantum cascade (QC) lasers has been determined using Fabry-Perot spectra obtained by operating the lasers in continuous wave mode below threshold. In the wavelength range of 5-8 μm, the global change of the group refractive index is as small as +8.2 × 10-3 μm-1. Using the method of Hakki and Paoli (1975), the subthreshold gain of the lasers has furthermore been measured as a function of wavelength and current. At the wavelength of best performance, 7.4 μm, a modal gain coefficient of 16 cm·kA-1 at threshold and a waveguide loss of 18 cm-1 have been estimated. The gain evolution confirms an earlier assumption that cross-absorption restricted laser action to above 6 μm wavelength. [ABSTRACT FROM PUBLISHER]

The authors demonstrate the viability of high-performance vertical cavity surface emitting lasers transmission with semiconductor optical amplifiers as a low-cost alternative to distributed-feedback erbium-doped fiber amplifier systems. They study the effect of the optical amplifier noise figure on metro networks. [ABSTRACT FROM PUBLISHER]

A chip-level integrated optoelectronic modulation circuit is described for high-speed digital interconnects. This circuit is composed of an electroabsorption modulator with surface-normal operation at 1550-nm wavelengths and a high-speed electronic driver. A growth/etch/regrowth procedure is used to fabricate the multiple-quantum well modulators and the heterojunction bipolar transistors (HBTs) of the circuit on a common InP substrate. The measured bandwidth is approximately 30 GHz [ABSTRACT FROM PUBLISHER]

A versatile, digital-alloy molecular beam epitaxy (MBE) technique is employed to grow lattice-matched and strained AlGaInAs multiple-quantum well (MQW) 1.58-μm laser diodes on InP. A threshold current density as low as 510 A/cm2 has been demonstrated for broad area lasers with 1% strained AlGaInAs MQWs, which is the best MBE result in this material system. A single facet pulsed power as high as 0.56 W is obtained. It is also found that the efficiency and internal loss of digital alloy AlGaInAs QW devices are comparable to lasers grown by conventional MBE [ABSTRACT FROM PUBLISHER]

We report the first observation of intersubband absorption at 1.3 μm in a coupled InGaAs-AlAsSb double-quantum-well structure lattice matched to InP substrate. The novel structure exhibits intersubband transitions concurrently at 1.3 and 1.55 μm due to the strong coupling of the intersubband states of the adjacent wells. A transient analysis of optical response in the multilevel conduction subband states for the designed structure indicates ultrafast optical switching behavior with a subpicosecond response [ABSTRACT FROM PUBLISHER]

Eight-channel wavelength-division-multiplexed (WDM) channel selectors were fabricated based on an monolithic integration of two arrayed-waveguide gratings and a semiconductor optical amplifier array on InP substrates. A compact device size of 5.2×3.6 mm2 was achieved with a combination of deep-ridge waveguides and buried waveguides. The device can select an arbitrary signal from a WDM signal with a low crosstalk of less than -40 dB, and fiber-to-fiber zero insertion loss operations were also achieved [ABSTRACT FROM PUBLISHER]

A 180-GHz monolithic sub-harmonic diode mixer is developed using 0.08-μm pseudomorphic InAlAs-InGaAs HEMT MMIC process on a 2-mil-thick InP substrate. This mixer demonstrates a conversion loss of better than 16.5 dB from 175 to 182 GHz with an LO drive of 13 dBm at 96 GHz. This is the first demonstration of a monolithic subharmonic HEMT diode mixer in this frequency range. The design and measurement of this monolithic microwave integrated circuit (MMIC) mixer and the waveguide-to-microstrip line transitions of the test-fixture are presented [ABSTRACT FROM PUBLISHER]