2.05-μm wavelength InGaAs-InGaAs distributed-feedbackmultiquantum-well lasers with 10-mW output power

Single-mode operation beyond 2.05-μm wavelength has been achieved in InGaAs-InGaAs distributed-feedback (DFB) laser with four quantum wells. The continuous-wave output power is 10.5 mW at a drive current of 200 mA and 25°C, The tuning range of the wavelength is between 2.051-2.056 μm with a temperature tuning rate of +0.125 nm/°C     

11.5-W CW 1.83-μm diode laser array

We demonstrate high-power operation of both individual broad-waveguide separate-confinement-heterostructure quantum-well InGaAsP-InP laser diodes and 1-cm-wide arrays emitting at 1.83 μm. Despite strong dependence of threshold current density and diode efficiency on operating temperature, a continuous-wave output power of 2.1 W has been obtained for 100-μm-aperture lasers with 2-mm-long cavities. An output power of 11.5 W was reached for ten element 1-cm-wide array at a heatsink temperature of 16°C     

2-μm GaInSb-AlGaAsSb distributed-feedback lasers

Room temperature continuous-wave operation of 2-μm single-mode InGaSb-AlGaAsSb distributed-feedback (DFB) lasers has been realized. The laser structure has been grown by solid source molecular beam epitaxy (MBE). Single-mode DFB emission is obtained by first-order Cr-Bragg gratings on both sides of the laser ridge. For a cavity with 900 μm length and 4 μm width, the threshold currents are around 20 mA and the continuous-wave output power is 10 mW at a drive current of 200 mA at 20°C. Monomode emission with sidemode suppression ratios of 31 dB has been obtained     

1.3-μm CW lasing of InGaAs-GaAs quantum dots at room temperaturewith a threshold current of 8 mA

We demonstrate the first 1.3-μm continuous-wave (CW) lasing at room temperature of self-assembled InGaAs-GaAs quantum dots. High-density 1.3-μm emission dots were successfully formed by the combination of low-rate growth and InGaAs-layer overgrowth methods of molecular beam epitaxy. The 1.3-μm ground-level CW lasing occurred at up to 40°C, and the threshold current of 8 mA at 25°C is less than one thirtieth of values ever reported for 1.3-μm dot pulse lasers. The achievement represents a milestone for creating quantum-dot lasers applicable to fiber-optic communication system     

MOVPE growth of a monolithic VCSEL at 1.56 μm in theInGaAlAs-InAlAs system lattice matched to InP

The first demonstration of a one-step-growth vertical-cavity surface-emitting laser (VCSEL) at 1.56 μm by low-pressure metal-organic vapor phase epitaxy in the InGaAlAs (λ_gap=1.43 μm)-InAlAs system lattice matched to InP is presented. The VCSEL's threshold current density was 7.5 kA/cm² and pulsed lasing had been obtained up to +55°C for 45-μm diameter proton implanted devices. This material system represents a high potential for continuous-wave VCSELs at 1.55-μm wavelength using a simple approach for large-scale industrial production     

High-power single-mode simplified antiresonant reflecting opticalwaveguide (S-ARROW) distributed feedback semiconductor lasers

Simplified antiresonant-reflective-optical-waveguide distributed-feedback semiconductor lasers based on Al-free InGaAs-InGaAsP-InGaP materials are reported for the first time. Devices with 6.5-μm-wide emitting apertures operate single-frequency (λ=0.968 μm) and single-spatial-mode to 157-mW continuous-wave output power. The full-width at half-maximum of the lateral far-field pattern is 4.5°, in excellent agreement with theory. Relative intensity noise values as low as -154 dB/Hz are measured between 500 MHz and 8 GHz     

Efficient continuous-wave lasing operation of a narrow-stripeoxide-confined GaInNAs-GaAs multiquantum-well laser grown by MOCVD

Efficient continuous-wave lasing operation has been achieved above room temperature by a triple-quantum-well GaInNAs-GaAs laser diode grown on a 6°-misoriented GaAs substrate by MOCVD. Using a planar, oxide-confined, narrow-stripe (8 μm) laser geometry, continuous-wave lasing operation was achieved over a wide range of temperatures up to 57°C. At room temperature, lasing occurs at a wavelength of 1.16 μm, with a high single-facet slope efficiency of 25% and a threshold current density of 1.3 kA/cm²     

High performance of 1.55-μm buried-heterostructurevertical-cavity surface-emitting lasers

We report a record low threshold current of 1.55-μm vertical-cavity surface-emitting laser (VCSEL). Thin-film wafer-fusion technology enables InP-based buried heterostructure VCSELs to be fabricated on GaAs-AlAs distributed Bragg reflectors. Threshold current density is independent of mesa size, and a 5-μm VCSEL exhibits a threshold current as low as 380 μA at 20°C and a single transverse mode up to the maximum optical output power under continuous-wave operation     

1.3-μm AlGaInAs buried-heterostructure lasers

1.3-μm AlGaInAs-InP strained multiple-quantumwell (MQW) buried-heterostructure (BH) lasers have been successfully fabricated. InP current blocking layers could be smoothly regrown using the simple HF pretreatment, although the etched active region includes Al-containing layers. The threshold current I_th was typically 11 mA for as-cleaved 350-μm-long devices, which is about 30% lower than that of the ridge laser counterparts. A maximum continuous-wave operating temperature as high as 155°C was achieved. For the 200-μm-long device with the high-reflective-coated rear-facet, I_th was as low as 7.5 mA and characteristic temperature T₀ was 80 K. The BH lasers also provided more circular far-field patterns and lower thermal resistances than for ridge lasers     

InGaAsP (λ=1.3 μm) strip buried heterostructure lasersgrown by MOCVD

The authors describe InGaAsP-InP index guides strip buried heterostructure lasers (SBH) operating at 1.3 μm with a 1.1-μm guiding layer grown by a two-step atmospheric pressure metalorganic chemical vapor deposition (MOCVD) growth procedure. These lasers are compared with buried heterostructure lasers having similar guiding layers under the active layer but terminated at the edge of the active layer. SBH lasers with 0.15-μm-thick active layer strips, 5-μm wide, and guide layers varying from 0 to 0.7 μm have threshold currents increasing from 34 to 59 mA, and nearly constant differential external quantum efficiencies of 0.2 mW/mA. The threshold current increases more rapidly with temperature with increasing guide layer thickness, with T₀ decreasing from 70°C for lasers without a guide layer to 54.3°C for lasers without a guide layer to 54.3°C for lasers with 0.7-μm-thick guide layers. Output powers of up to 30 mW/facet have been obtained from 254-μm-long lasers and were found to be insensitive to guide layer thickness     

A temperature-dependent DC model for quarter-micron LDD pMOSFET'soperating in a Bi-MOS structure

A temperature-dependent analytical model for deep submicrometer LDD p-channel devices operating in a Bi-MOS structure is reported for the first time. This model is based on experimental data obtained from 0.25-μm process wafers with a wide range of technologies (0.25-1.0 μm). The measurements have been performed within the temperature range 223-398 K (-50°C to +125°C). The model accounts for the effects of independently biasing the source, drain, gate and body potentials, scaling, and the influence of temperature on the threshold voltage and the device currents. The effect of temperature on the device transconductance and the output conductance have also been examined. The results revealed that close agreement between the analytical model and the experimental has been achieved. Comparisons between the principal MOS current and the lateral bipolar current have been made to demonstrate the improvement of the latter with temperature for the quarter-micron devices     

Characteristics of GaAsSb single-quantum-well-lasers emitting near1.3 μm

We report data on GaAsSb single-quantum-well lasers grown on GaAs substrates. Room temperature pulsed emission at 1.275 μm in a 1250-μm-long device has been observed. Minimum threshold current densities of 535 A/cm² were measured in 2000-μm-long lasers. We also measured internal losses of 2-5 cm^-1, internal quantum efficiencies of 30%-38% and characteristic temperatures T₀ of 67°C-77°C. From these parameters, a gain constant G₀ of 1660 cm^-1 and a transparency current density J_tr of 134 A/cm² were calculated. The results indicate the potential for fabricating 1.3-μm vertical-cavity surface-emitting lasers from these materials     

Continuous-wave operation of 1.30μm GaAsSb/GaAs VCSELs

1.30 μm VCSELs using GaAsSb quantum wells, which operate continuous-wave at and above room temperature (RT), are reported. A threshold current as low as 1.2 mA at RT and a maximum CW operating temperature of 70°C are demonstrated     

High-power 2.0 μm InGaAsP laser diodes

Data detailing the performance of strained-layer InGaAs/InGaAsP double-quantum-well laser diodes operating at 2.0 μm are presented. The total external efficiency and maximum power achieved are 55% and 1.6-W continuous wave (CW), respectively, from a 200-μm gain-guided laser diode. Measurements on gain-guided broad area devices yield an internal efficiency of 0.73 with a distributed loss coefficient, α, of 7.5 cm^-1. The measured threshold current density is 300 A/cm² for a 2-mm-long broad area device operated CW at 25°C     

CW high power single-lobed far-field operation of long-cavityAlGaAs-GaAs single-quantum-well laser diodes grown by MOCVD

Data on long-cavity 100-μm-wide broad-stripe laser diodes that lase with a barrow single-lobed far-field pattern in continuous room-temperature operation are presented. Diodes with a cavity length of 1250 μm emit a power of 200 mW per facet into a 2.5° lobe (full width at half maximum). Short-cavity devices (cavity length of 350 μm) lase with a continuously increasing number of lateral modes right from threshold, and exhibit a far-field divergence that is over three times greater than that of 1250-μm diodes. Explanations for the effect of increasing cavity length on the field patterns of these devices are proposed, based on the measured increase in injected carrier diffusion length in long-cavity diodes and the influence of thermal waveguiding and mirror losses on intermodel discrimination     

High-temperature operating 1.3-μm quantum-dot lasers fortelecommunication applications

High-performance 1.3-μm-emitting quantum-dot lasers were fabricated by self-organized growth of InAs dots embedded in GaInAs quantum wells. The influence of the number of quantum-dot layers on the device performance was investigated. Best device results were achieved with six-dot layers. From the length dependence; a maximum ground state gain of 17 cm^-1 for six dot layers could be determined. Ridge waveguide lasers with a cavity length of 400 μm and high-reflection coatings show threshold currents of 6 mA and output powers of more than 5 mV. Unmounted devices can be operated in continuous wave mode up to 85°C. A maximum operating temperature of 160°C was achieved in pulsed operation for an uncoated 2.5-mm-long ridge waveguide laser     

Infrared imaging using uncooled focal plane arrays of unreticulated10-μm potassium tantalum niobate films

Potassium tantalum niobate (KTN) films, 10-μm thick, with a nominal Curie temperature of -20°C were formed on polished platinum-coated sacrificial yttria substrates by metalorganic deposition (MOD). These KTN films were used to fabricate focal plane arrays consisting of 128×128 pixels with each pixel on 50-μm centers and 50-μm². Using f/1 optics and a 2.5-V/μm ² detector bias, a noise equivalent temperature (NEΔT) of 0.65°C was obtained for the best 1% of the pixels when the detector and blackbody source operated at 25°C     

Single transverse mode operation of 1.55-μm buriedheterostructure vertical-cavity surface-emitting lasers

In this letter, we report the single-mode operation of 1.55-μm buried heterostructure vertical-cavity surface-emitting lasers (VCSELs) fabricated on a GaAs-AlAs distributed Bragg reflector using thin-film wafer fusion. A 7-μm VCSEL exhibits a single transverse mode at up to about 0.1-mW maximum optical output power and 75°C maximum operation temperature under continuous-wave operation     

Static and dynamic characteristics of 1.29-μm GaInNAsridge-waveguide laser diodes

Rapid progress has been made in the growth of GaInNAs-GaAs by solid source molecular beam epitaxy, leading to significant improvements of such heterostructures for 1.3-μm wavelength laser emission. We report on growth, device fabrication and characteristics of ridge-waveguide lasers in this material system. Performance data of these devices (emission at λ=1.29 μm, threshold currents of 16 mA, slope efficiencies of 0.35 W/A per facet, and continuous-wave (CW) operation at 100°C) prove that this new material can successfully compete with the well matured InGaAsP-InP system. Furthermore, the very first small-signal modulation measurement results of laser diodes in this novel material-system as well as first ageing results are presented     

155 W CW optical power from 1 cm monolithic AlGaAs/InGaAs laserdiode array

155 W continuous-wave output power from a 1 cm wide monolithic AlGaAs/InGaAs laser diode array with an emitting aperture of 4800 μm has been demonstrated at a cooling water temperature of 3°C. A continuous-wave output power of 72 W was achieved at room temperature with an emitting aperture of 1600 μm. High T₀ was observed for the laser structures