掩埋弯月形InGaAsP/InP激光器稳态特性研究

本文对掩埋弯月形InGaAsP/InP激光器的稳态特性作了数值计算和理论分析。对有源层栽流子浓度分布的剖面形状给予解释,并分析了结构参数对激光器阈值电流的影响。计算结果和实验符合较好。     

InGaAsP InP current confinement mesa substrate buried heterostructure laser diode fabricated by one-step liquid-phase epitaxy

New InGaAsP/InP buried heterostructure laser diodes fabricated by one-step liquid-phase epitaxy are described, in which the InGaAsP active region completely embedded in InP is grown on the top of the mesa stripe formed on the InP substrate while, simultaneously, current confinement structure is automatically formed on both sides of the mesa stripe. These current confinement mesa substrate buried heterostructure laser diodes (CCM-LD's) have current confinement structure which very effectively blocks unwanted leakage current bypassing the light emitting region which has enabled laser operation with a threshold current as low as 20 mA, 70-mW maximum CW output at room temperature, and 125°C maximum CW operation temperature. Life tests over 6000-h CW operation at 70°C and 5 mW/facet have confirmed good reliability of these devices.     

Transverse mode control in InGaAsP/InP buried crescent diode lasers

Transverse mode stabilisation of InGaAsP/InP buried crescent laser diodes emitting at 1.3 ?m is described. Width and thickness of the active region have been reduced to stabilise the transverse mode. Operation up to 17 mW/facet in a stable transverse mode and threshold current as low as 12 mA in CW operation have been obtained.     

InGaAsP/InP buried crescent laser diode emitting at 1.3 µm wavelength

The fabrication procedure, designing of an active region and a p-n-p-n current blocking structure, characteristics and the aging results of an InGaAsP/InP buried crescent (BC) laser diode are described. The BC laser diodes exhibit high laser performances, such as a low-threshold current, a fundamental transverse mode oscillation with linear light output-current characteristics. CW operation at as high as 100°C is achieved with a junction up configuration as a result of the improvement in the current blocking structure. A stable CW operation at 80°C has been realized with a constant optical output power of 5 mW.     

Low threshold channelled-substrate buried crescent InGaAsP lasers emitting at 1.54 ?m

Double-heterostructure lasers with crescent-shaped InGaAsP active layers have been fabricated with CW emission of 1.54 ?m. Lowest CW thresholds are 45?47 mA for a 200 ?m long cavity at 25°C. The lasing near-field widths are 2.5?3.0 ?m and the spectral widths to 10% of peak are 4?5 nm under both CW conditions and modulation up to 320 Mbit/s.     

V-grooved substrate buried heterostructure InGaAsP/InP laser

A V-grooved substrate buried-heterostructure laser emitting at 1.3 ?m wavelength is described. The active layer is buried in the V-shaped groove. A CW threshold current of 10~20 mA is obtained and a far-field pattern free from irregularity and peak shift is realised. Damped relaxation oscillation and stable aging characteristics are obtained.     

Degradation mechanism in 1.3 ?m InGaAsP/InP buried crescent laser diode at a high temperature

A leakage current flowing through a junction between a p-InP current blocking layer and an n-InP cladding layer is examined in connection with a degradation of a buried crescent laser diode at a high temperature. The degradation characteristics have been successfully explained by a theoretical model proposed in this study.     

InGaAsP planar buried heterostructure laser diode (PBH-LD) with very low threshold current

Using a new LPE growth technique, an InGaAsP/InP planar buried heterostructure laser diode (PBH-LD) has been realised in 1.3 and 1.5 ?m wavelength regions. As a result of the effective carrier confinement, CW threshold currents as low as 8.5 mA and 13 mA have been obtained in 1.3 and 1.5 ?m PHB-LDs, respectively, at room 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.     

InGaAsP/InP distributed feedback buried heterostructure lasers with both facets cleaved structure

Feasibilities of InGaAsP/InP distributed feedback buried heterostructure lasers in the 1.3 and 1.5 μm wavelength regions with two cleaved facets are shown. Theoretical and experimental examinations show that the kL values ranging between 1 and 2 are sufficient for high-performance operation with the stable single longitudinal mode in a temperature range wider than 100 degrees. Distribution of lasing characteristics is investigated for 140 randomly chosen LD's from two wafers. Approximately 65 percent of the devices are found to be operable in the single longitudinal mode. A CW single longitudinal mode operation power of 20 mW at 25°C for a 1.5 μm device, and that of 40 mW (60 mW with AR coating) at 25°C for a 1.3 μm device with low threshold current are achieved. These characteristics are attained by both first- and second-order grating devices fabricated by the PH3addition LPE technique. The results of the aging test at 70°C and 110 mA in the automatic current control condition are also presented.     

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.<>     

Low-loss fibre-chip coupling by buried laterally tapered InP/InGaAsP waveguide structure

A passive InP/InGaAsP spot-size transformer for low-loss coupling of semiconductor optoelectronic devices to single-mode fibres has been fabricated entirely on InP. Using a buried two-layer laterally tapered section, spot-size transformation is demonstrated from below 2 mu m up to 8 mu m, the spot size of a dispersion-shifted fibre at 1550 nm. For a chip without antireflection coating a total insertion loss of 2.7 dB was achieved at a taper length of approximately 600 mu m.<>     

Channelled substrate buried heterostructure InGaAsP/InP laser emitting at 1.55 ?m

An InGaAsP/InP channelled substrate buried heterostructure (c.s.b.) laser emitting at 1.55 ?m is fabricated by channel etching and single-stage l.p.e. growth without a low temperature growth technique or antimeltback layer. The c.s.b. laser shows low threshold current at room temperature c.w. operation and stable single transverse mode operation.     

High-speed InGaAsP/InP multiple-quantum-well laser

The authors describe practical high-speed InGaAsP/InP lasers based on compressively strained quantum wells. Buried heterostructure lasers with threshold currents of 10 mA and slope efficiencies of 0.23 mW/mA are used. A modulation bandwidth of 20 GHz is obtained at a low drive current of 90 mA. A K factor of 0.25 ns is obtained and the intrinsic bandwidth of these lasers is estimated at 35 GHz     

Low threshold 1.55 ?m InGaAsP lasers double clad with InGaAsP confining layers

Preliminary results for 1.55 ?m InGaAsP double-heterostructure lasers with symmetrical InGaAsP confining layers are presented. The lowest broad-area threshold is 1.36 kA/cm2, which is 30% lower than the best value previously reported for 1.55 ?m lasers. This improvement is believed to be related to the absence of terracing on InGaAsP confining layers.     

Extremely low threshold current 1.52 ?m InGaAsP/InP MS-DFB lasers with second-order grating

Threshold currents of 1.52 ?m InGaAsP/InPGaAsP/InP DFB lasers with second-order gratings have been reduced to 12 mA in single-longitudinal-mode operation. External differential efficiencies exceed 25%/feet with a ?/4 Si3N4 coating on the front facet.     

Low threshold current CW operation of GaInAsP/InP buried heterostructure distributed Bragg-reflector integrated-twin-guide laser emitting at 1.5?1.6 ?m

Low threshold current CW operation of a 1.5?1.6 ?m-wavelength GaInAsP/InP buried heterostructure distributed Bragg reflector integrated twin guide (BH-DBR-ITG) laser was obtained up to 12°C. Single wavelength operation was obtained at a temperature range of 25 deg. The temperature dependence of lasing wavelength was 0.10 nm/deg. At 248 K, the threshold current, the differential quantum efficiency and the maximum output power were 37 mA, 16.3%/facet and 6 mW, respectively.     

High power output InGaAsP/InP buried heterostructure lasers

A novel InGaAsP/InP buried heterostructure (BH) laser was fabricated on a p-InP substrate. This laser can provide a peak pulse output of 0.8 W per facet with a stable lateral transverse mode oscillation and enables the fault location measurement of a single mode fibre cable over 20 km.     

1.55 μm InGaAsP/InP laser buried in a high-resistivity epitaxiallayer on a semi-insulating InP substrate

A buried heterostructure (BH) 1.55 μm laser embedded in a high resistivity epitaxial layer on a semi-insulating substrate is described. This device has a planar surface and both a p- and an n-type electrode on the same side, facilitating integration of electronic devices. Its threshold current is typically 9 mA. Its small signal 3 dB modulation bandwidth was 14 GHz due to the reduction of device resistance and capacitance. No degradation was observed in an aging test at 50°C even after more than 3000 h     

Single-mode operation of 1.3 µm InGaAsP/InP buried crescent lasers using a short external optical cavity

Highly single longitudinal mode operation of 1.3 μm InGaAsP/InP buried crescent lasers has been obtained using a60-600 mum long external cavity defined by a spherical mirror. The intensity of the neighboring modes was suppressed by a factor of 1200 for dc excitation and by a factor of 800 for combined dc and 250 MHz current modulation.