1.7–1.8 µm Diode lasers based on quantum-well InGaAsP/InP heterostructures

Separate-confinement InGaAsP/InP heterostructures with highly strained quantum wells are grown by metal-organic vapor-phase epitaxy (MOVPE). The properties of InGaAsP and InGaAs quantum wells are studied, and the influence of the heterostructure parameters on the lasing wavelength is analyzed. The grown structures are used for designing high-intensity multimode and single-mode mesa-stripe laser diodes operating in the range λ=1.7–1.8 µm. The maximum continuous-wave lasing power achieved at room temperature is 1.6 W and 150 mW for multimode and single-mode laser diodes, respectively. Single-mode lasing is retained up to 100 mW.     

The growth of high quality InP/InGaAs/InGaAsP interfaces by CBE for SCH multi-quantum well lasers

Bulk InGaAsP and heterointerfaces of InP/InGaAs and InGaAsP/InGaAs have been grown by chemical beam epitaxy for use in multi-quantum well separate confinement heterostructure lasers. InGaAsP has been successfully grown for λ=1.1, 1.2 and 1.4 μm. The TMI and TEG incorporation coefficients have strong dependencies on substrate temperature and also charge as the InGaAsP composition tends towards InP. InP/InGaAs and InGaAsP/InGaAs quantum wells have been grown to determine the optimum gas switching sequence to minimize the measured photoluminescence FWHM. InGaAs quantum wells as narrow as 0.6 nm have been grown with 7K FWHM of 12.3 meV. Lattice matched MQW-SCH lasers were grown using different interface switching sequences with the best laser having a threshold current density of 792A/cm² for an 800 × 90 μm broad area device.     

微碟激光器的单模低阈值激射

简单分析了碟型微腔激光器中的激射模式及自发发射系数。采用反应离子刻蚀和选择性刻蚀方法蚀刻出InGaAs InGaAsP多量子阱 (MQW)碟型激光器 ,碟直径 3 μm ,在液氮温度下进行光抽运实验 ,观察其模式特性。实现了单模激射 ,波长 1 5 μm ,抽运阈值 18μW。     

MBE-grown Ridge-waveguide InGaAs/InGaAsP Strained Quantum Well Lasers at 2 μm Wavelength

The result of molecular beam epitaxy (MBE)-grown ridge-waveguide InGaAs/ InGaAsP/InP strained quantum well lasers at 2 μm wavelength is reported. The pulsed electrical luminescence spectrum at room temperature is observed with peak wavelength of about 1.98 μm. At 77 K the lasers become lasing in pulse regime, with threshold current of about 18～30 mA, peak wavelength of about 1.87～ 1. 91 μm, and single longitudinal mode operation in the current range of 160～230 mA.     

High power single-mode (λ=1.3–1.6 μm) laser diodes based on quantum well InGaAsP/InP heterostructures

The possibility of achieving maximal optical output power in the single-mode lasing for mesa-stripe laser diodes fabricated on the basis of InGaAsP/InP quantum-well heterostructures with separate confinement have been studied both experimentally and theoretically. The basic condition for the single-mode lasing of laser diodes in a wide range of driving currents is shown to be the precise choice of the effective refractive index Δn _L discontinuity in the plane parallel to the p-n junction. A InGaAsP/InP separate confinement heterostructure with a step waveguide, with a threshold current density of 180 A/cm² and an internal quantum efficiency of stimulated emission of 93–99%, has been manufactured via the MOCVD method. The optimization of the mesa-stripe diode design for the developed InGaAsP/InP heterostructure is carried out with the aim of achieving maximal optical output power in the case of single-mode lasing. An output power of 185 mW is attained in the laser diode with the mesa-stripe width W=4.5 μm (λ=1480 nm). The maximal continuous output power was as high as 300 mW. The full width at half-maximum (FWHM) of the lateral far-field pattern increased by 1° relative to the threshold value.     

High-temperature operation of InGaAs/InGaAsP compressive-strainedQW lasers with low threshold currents

We investigated the influence of the band gap wavelength of barrier layers and separate confinement heterostructure (SCH) layers λ_SCH on the high-temperature operation of InGaAs/InGaAsP compressive-strained quantum-well (QW) lasers. The optimum λ_SCH was 1.2 μm, at which carriers were sufficiently confined into quantum wells. The QW laser with λ_SCH = 1.2 μm exhibited low threshold currents of 2.3 mA at 20°C and 9.7 mA at 100°C and CW lasing up to 150°C     

1.5?1.7 ?m v.p.e. InGaAsP/InP c.w. lasers

Room temperature c.w. lasing operation has been achieved at 1.55 ?m with InGaAsP/InP devices and at 1.65 ?m with InGaAs/InP devices prepared via vapour-phase epitaxy. Lasing threshold currents vary as exp (T ? 20)/T0 with 40相似文献   

GSMBE生长1.8-2.0μm波段InGaAs/InGaAsP应变量子阱激光器

报道了气态分子束外延(GSMBE)生长1.8—2.0μm波段InGaAs/InGaAsP应变量子阱激光器的研究结果．1.8μm波段采用平面电极条形结构,已制备成功10μm和80μm条宽器件,器件腔长500μm,室温下光致发光中心波长约为1.82μm,在77K温度下以脉冲方式激射,阈值电流分别约为250mA和600 mA,中心波长分别在1.69μm和1.73μm附近． 2.0μm波段,制备成功8μm宽脊波导结构器件,器件腔长500μm,室温光致发光中心波长约为1.98μm,77K温度下以脉冲方式激射,阈值电流约为 20mA,中心波长约为1.89μm,其电流限制和纵模限制效果优于平面电极条形结构器件．     

Saturation of light-current characteristics of high-power laser diodes (λ = 1.0–1.8 μm) under pulse operation

Spectral and light-current characteristics of separate-confinement lasers that are based on InAl-GaAs/InP and InGaAsP/InP alloys and emit in the wavelength range of 1.5–1.8 μm are studied at high excitation levels (up to 80 kA/cm²) in pulse operation (100 ns, 10 kHz). It is shown that the peak intensity in the stimulated-emission spectrum saturates as the pump current is increased. Further increase in the emitted power is attained owing to the emission-spectrum broadening to shorter wavelengths, similar to lasers on the GaAs substrates (λ = 1.04 μm). It is established experimentally that the broadening of the stimulated-emission spectrum to shorter wavelengths is caused by an increase in the threshold current and by an increase in the charge-carrier concentration in the active region. This concentration increases by a factor of 6–7 beyond the lasing threshold and can be as high as 10¹⁹ cm^?3 in pulse operation. It is shown that saturation of the light-current characteristics in pulse operation takes place in the InAlGaAs/InP and InGaAsP/InP lasers as the pump current is increased. It is shown experimentally that there is a correlation between saturation of the light-current characteristic and an increase in the threshold current in the active region. An increase in the charge-carrier concentration and gradual filling of the active region and waveguide layers with electrons are observed as the pump current is increased; stimulated emission from the waveguide is observed at high pump currents.     

1．55μm InGaAsP／InPDH激光器中的0．95μm发光带与Auger复合

报道了在１．５５μｍＩｎＧａＡｓＰ／ＩｎＰ激光器中发现的０．９５μｍ波长高能发光峰的一系列实验结果，并通过分析肯定了ＩｎＧａＡｓＰ有源区的Ａｕｓｅｒ复合是造成载流子向两侧ＩｎＰ限制层漏泄的主要原因，也是影响１．５５μｍＩｎＧａＡｓＰ／ＩｎＰＤＨ激光器Ｔ０值的主要因素。     

新型长波长InP基谐振腔增强型光探测器

介绍了一种新型长波长InP基谐振腔增强型(RCE)光探测器。通过V(FeCl3):V(H2O)溶液对InGaAs牺牲层的选择性湿法腐蚀,制备出具有InP/空气隙的高反射率分布布拉格反射镜(DBR),并将该选择性湿法腐蚀技术成功地应用到长波长InP基谐振腔增强型光探测器的制备中去,从而彻底解决了InP/InGaAsP高反射率分布布拉格反射镜难以外延生长的问题。所制备出的谐振腔增强型光探测器,其台面面积为50μm×50μm,底部反射镜为1.5对的InP/空气隙分布布拉格反射镜,顶部反射镜靠InGaAsP与空气的界面反射来实现。测试结果表明,该谐振腔增强型光探测器在波长1.510μm处获得了约59％的峰值量子效率,在3V反偏压下暗电流为2nA,3dB响应带宽达到8GHz。     

Intermixing of InP-based multiple quantum wells for integrated optoelectronic devices

The intermixing characteristics of three widely used combinations of InP-based quantum wells (QW) are investigated using the impurity-free vacancy disordering (IFVD) technique. We demonstrate that the bandgap energy shift is highly dependent on the concentration gradient of the as-grown wells and barriers, as well as the thickness of the well, with thinner wells more susceptible to interdiffusion at the interface between the barrier and well. According to our results, the InGaAsP/InGaAsP and InGaAs/InP are well suited for applications requiring a wide range of bandgap values within the same wafer. In the case of the InGaAs/InGaAsP system, its use is limited due to the significant broadening of the photoluminescence spectrum that was observed. The effect of the top InGaAs layer over the InP cladding is also investigated, which leads to a simple way to obtain three different bandgaps in a single intermixing step.     

Strained layer (1.5 μm) InP/InGaAsP lasing opto-electronicswitch (LOES)

We present for the first time a lasing opto-electronic switch (LOES) fabricated in the InP/InGaAsP system. In this device the active region is composed of four 63 Å compressively strained quantum wells. A lasing threshold of 104 mA, or 6933 A/cm², has been observed at a temperature of 298 K, with an external differential quantum efficiency of 14%. The lasing wavelength is centered at 1.52 μm. The current-voltage characteristics manifest pronounced differential negative resistance, characterized by switching and holding voltages of 6.8 V and 1.6 V, respectively, and a switching current density of 33 A/cm². The OFF and ON state resistances are approximately 150 kΩ and 4 Ω, respectively     

Performance of Hybrid Laser Diodes Consisting of Silicon Slab and InP/InGaAsP Deep‐Ridge Waveguides

The fundamental transverse mode lasing of a hybrid laser diode is a prerequisite for efficient coupling to a single‐mode silicon waveguide, which is necessary for a wavelength‐division multiplexing silicon interconnection. We investigate the lasing mode profile for a hybrid laser diode consisting of silicon slab and InP/InGaAsP deep ridge waveguides. When the thickness of the top silicon is 220 nm, the fundamental transverse mode is lasing in spite of the wide waveguide width of 3.7µm. The threshold current is 40 mA, and the maximum output power is 5 mW under CW current operation. In the case of a thick top silicon layer (1 µm), the higher modes are lasing. There is no significant difference in the thermal resistance of the two devices.     

Low threshold, room temperature pulsed operation of 1.5 μmvertical-cavity surface-emitting lasers with an optimized multi-quantumwell active layer

Room temperature, pulsed operation of 1.5 μm vertical-cavity surface-emitting laser is demonstrated by the optimization of an InGaAs/InGaAsP multi-quantum well active layer, especially the number of quantum wells and the barrier thickness considering matched gain effect. Low threshold currents of 17 mA in 5×7 μm²-devices and 25 mA in 7×10 μm²-devices were achieved     

1.3μm低阈值InGaAsP/InP应变补偿MQW激光器的LP-MOCVD生长

报道了用低压金属有机物化学气相淀积（ＬＰ－ＭＯＣＶＤ）方法外延生长ＩｎＧａＡｓＰ／ＩｎＰ应变补偿多量子阱结构。用此材料制备的掩埋异质结（ＢＨ）条形结构多量子阱激光器具有极低阈值电流４～６ｍＡ。２０～４０℃时特征温度Ｔ０高达６７Ｋ，室温下外量子效率为０．３ｍＷ／ｍＡ。     

Analysis of electrical, threshold, and temperature characteristics of InGaAsP/InP double- heterojunction lasers

This paper presents an extensive study of the fundamental characteristics of InGaAsP/InP double-heterojunction (DH) lasers with a wavelength of 1.3 μm. The confinement properties of injected carriers in the quaternary active region, the electrical properties such as leakage current and diode current versus voltage, the threshold characteristics, and the threshold temperature characteristics are determined through an analysis of the heterojunction energy band structure. The threshold temperature characteristics and the carrier leakage from the active region into the confining layers are examined in detail. To clarify the dependence of carrier leakage on lasing wavelength in InGaAsP/InP DH lasers and to explain the difference between GaAlAs/GaAs DH and InGaAsP/InP DH lasers, the barrier heights required to effectively confine the injected carriers and the effective carrier masses in the active region are discussed. Various possible explanations for the observed threshold temperature characteristics are considered.     

Gain and carrier lifetime measurements in AlGaAs multiquantum well lasers

We have measured the gain and the carrier lifetime at threshold in shallow proton stripe AlGaAs multiquantum well lasers with several different active layer structures. The lasers studied had active layers with two wells, four wells, six wells, and the modified multiquantum well. The net gainGis found to vary almost linearly with the injection currentIfor all the laser structures studied. The slopedG/dIis largest for the modified multiquantum well (MMQW) laser which is consistent with the observed lowest threshold current of these devices. We find that the carrier density at threshold for the MMQW laser is about a factor of 4 lower than that for a single quantum well laser. Thus, the effect of a nonradiative mechanism (e.g., Auger effect) which varies superlinearly with the injected carrier density is considerably reduced in MMQW lasers compared to that in single quantum well (SQW) lasers or the conventional double heterostructure lasers. The reduced threshold carrier density of the MMQW lasers has important implications for high temperature performance of lasers fabricated from the InGaAsP/InP material systems which are believed to have nonradiative mechanisms that vary superlinearly with carrier density, particularly for those laser structures for which the high temperature operation is not limited by leakage current.     

Detuning adjustable multiwavelength MQW-DFB laser array grown byeffective index/quantum energy control selective area MOVPE

A multiwavelength MQW DFB laser array with novel structure Is described. Oscillation wavelength and gain peak wavelength were simultaneously controlled on the same epitaxial wafer by using modulated grown thicknesses of selectively grown InGaAs/InGaAsP/InP MQW active waveguides. The laser array with constant-pitch built-in corrugation fabricated by a simple DFB laser process demonstrated 10.1 nm controllable range for lasing wavelength and 45 nm for gain peak wavelengths, with uniform lasing properties and narrow spectral linewidths. The technique is attractive for light sources used in WDM/FDM applications     

Ultra high-speed InP/InGaAs DHBTs with ft of 203 GHz

InP/InGaAs/InP double heterojunction bipolar transistors (DHBTs) were designed for wide band digital and analog circuits, and fabricated using a conventional mesa structure with benzocyclobutene (BCB) passivation and planarization process techniques. Our devices exhibit a maximum ft of 203 GHz, which is the highest ft for DHBTs in mainland China. The emitter size is 1.0×20 μm2. The DC current gain β is 166, and BVCEO=4.34 V. The devices reported here employ a 40 nm highly doped InGaAs base region and a 203 nm InGaAsP composite structure. They are suitable for high speed and intermediate power applications.