Attenuation measurements on MOCVD-grown GaAs/GaAlAs optical waveguides

We report loss measurements on MOCVD-grown GaAs/GaAlAs optical waveguides, by sequential cleaving with allowance for Fabry-Perot resonator effects. Upper bound values are 1.4 dB/cm for strip-loaded and 2.5 dB/cm for fully etched ridge waveguides.     

InP/benzocyclobutene optical nanowires

A report is presented on the optical propagation loss of waveguides based on InP nanowires embedded in a benzocyclobutene matrix and fabricated through a wafer bonding process. Propagation loss was evaluated on waveguides of varying width; it can be as low as 0.8 dB/mm for a 300 x 300 nm InP.     

欧姆接触最佳合金条件

本文比较详细地介绍了GaAs和InP半导体激光器欧姆接触中合金的最佳条件,并从金属学观点对此进行了理论分析.     

离散谱折射率法优化设计深刻蚀、单模GaAs/GaAlAs脊形光波导

采用离散谱折射率法对深刻蚀GaAs/GaAlAs多层脊形光波导的特性作了详细的理论分析,并对所获得的较大截面、低损耗的单模脊形光波导的制作容差性作了进一步的分析．计算表明,用离散谱折射率法获得的单模脊形光波导具有较大的制作容差性．     

离散谱折射率法优化设计深刻蚀、单模GaAs/GaAlAs脊形光波导

采用离散谱折射率法对深刻蚀 Ga As/ Ga Al As多层脊形光波导的特性作了详细的理论分析 ,并对所获得的较大截面、低损耗的单模脊形光波导的制作容差性作了进一步的分析 .计算表明 ,用离散谱折射率法获得的单模脊形光波导具有较大的制作容差性 .     

InP/InGaAsP条形半导体激光器中的瞬态温度特性理论计算

本文首次通过建立二维热传导模型,给出了条形InP/InGaAsP四元系半导体激光器中的瞬态热特性的理论计算结果,它包括了在几种条件下,激光器管芯内温度的空间分布随阶跃电注入的时间变化关系.计算结果表明四元系条形激光器体内温度升高比三元系GaAs/GaAlAs激光器的温升低,有关原因在文中给予讨论.     

Mach-Zehnder modulators and optical switches on III-Vsemiconductors

Key components of interferometric structures, i.e., phase modulators and beamsplitters, as well as a Mach-Zehnder modulator are investigated. Inverted rib waveguide phase modulators have been fabricated using vapor phase epitaxy (GaAs and InP homostructures) or a combination of vapor phase epitaxy and metal-organic vapor phase epitaxy (GaAlAs/GaAs double heterostructure). Two different beamsplitters, the three-guide coupler and the etched semitransparent mirror, have been studied both experimentally and theoretically. Experimental results have been obtained by fabricating semitransparent mirrors with the reactive ion etching. Using the three guide coupler, a GaAs homostructure Mach-Zehnder modulator has been realized. The required switching voltage is -14 V for 6-mm-long electrode and a crosstalk of 18 dB has been measured. The use of the semitransparent mirror for Mach-Zehnder interferometers is also discussed. In order to minimize the diffraction losses, the use of higher order waveguides, rather than single-mode waveguide looks promising     

New contact resistance profiling method for the assessment of III?V alloy multilayer structures

A practical technique for the assessment of multilayer III?V structures is described which is based on the measurement of the contact resistance between a tungsten carbide probe and an angle lapped sample surface. The technique has been applied to homostructure and double heterostructure layers of GaAs, GaAlAs, InP and GaInAsP and quantitative information on the doping profiles has been obtained by calibration against binary material samples of known impurity levels.     

Single-mode optical waveguides and phase modulators in the InP material system

The characteristics of several different single-mode optical waveguides in the InP material system are discussed. Slab-coupled rib waveguides in GaInAsP (lambda_{gap} approx 1 mum) epitaxial layers grown on InP have shown propagation losses as low as 1.7 cm^-1at 1.3 μm and 2.7 cm^-1at 1.15 μm. Oxide-confined InP rib guides fabricated using a lateral overgrowth technique have losses of about 1.5 cm^-1at 1.15 μm. Three-guide couplers have been made by fabricating three parallel oxide-confined guides in close proximity. InP p+-n-n+ guides capable of modulating TE-polarized radiation have been fabricated using epitaxial techniques and Be-ion implantation. By measuring the phase difference between the TE-like and TM-like modes as a function of applied voltage, an estimate of the r41electrooptic coefficient in InP at 1.3 μm that is in good agreement with a previously reported value was obtained. Guides of this type should find use as the active components in InP switches and interferometers.     

A comparison between finite element calculations and experimentalresults on InGaAsP/InP waveguides

Calculated and measured properties of InGaAsP/InP waveguides are compared. The spectral response of Bragg gratings was used to measure precisely the effective indexes of the guided modes of InGaAsP/InP waveguides. The shape of the near fields and the effective refractive indexes of waveguides, which support more than one guided mode, show an excellent agreement between theory and experiment. It is shown that rigorous calculation methods such as the finite-element method can be used to predict exactly the optical properties of integrated devices     

金属覆盖型光波导极化器的分析和设计

本文通过精确求解波导的本征方程，针对光波导极化器，分析了金属覆盖四层光波导中ＴＭ模随缓冲层参数变化的特性，指出了存在于其中的模式共振点，根据模式共振点的特点给出了金属覆盖型光波导化器的优化设计原则，最后讨论了使用ＣａＡｓ／ＧａＡｌＡｓ材料制作光波导极化器的意义。     

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.     

An improved approach and experimental results of a low-frequency noise measurement technique used for reliability estimation of diode lasers

In this paper, we give the experimental results of low-frequency noise measurement and reliability forecasting after we have studied the low-frequency noise and electric ageing of 23 GaAs/GaAlAs proton-bombarded heterostructure LDs and 21 V-groove InP/InGaAsP lasers. We discuss the measuring circuits, measuring parameters, and suggest an improvement.     

Monolithic integration of optoelectronic, electronic and passive components in GaAlAs/GaAs multilayers

The monolithic integration of LEDs, detectors, waveguides, resistors and FETs has been demonstrated in GaAlAs/GaAs multilayer structures. The resulting uncommitted optoelectronic integrated circuits have been operated in transmitter, receiver and repeater configurations.     

All optical multiple-quantum-well waveguide switch

By increasing the input light intensity to a GaAs/GaAlAs multiple-quantum-well waveguide, an induced phase shift of up to ? radians has been detected. Partial switching of light between two such coupled waveguides by variation of the input light intensity has been observed for the first time.     

Low-loss bent connections for optical switches

We present S-bent InP/InGaAsP rib waveguides used as connections for optical switches at λ=1.5 μm. Transitions between waveguides of different curvature and different lateral confinement are realized with adiabatic tapers. We investigated bends with radii from 200-1700 μm and rib widths 2.2, 3.2, and 4.2 μm. For rib width 3.2 μm we obtain almost for all radii extremely small quasi-polarization independent excess-losses below 0.3 dB. The waveguides are easy to fabricate and the tapered transitions are tolerant to technological variations. The performance offers the chance of low cost and simple monolithic integration of large optical switch matrices in InP/InGaAsP     

Simple and accurate loss measurement technique for semiconductor optical waveguides

Loss figures for GaAs/GaAlAs heterostructure optical waveguides have been derived from Fabry-Perot cavity resonances. These correlate with the mean guide transmissions within ±0.5 dB for 75% of the guides measured, for losses up to 12 dB per pass.     

Passive optical GaInAsP/InP waveguides

We have fabricated GaInAsP/InP rib waveguides with lengths of up to 7 mm and widths between 2.5 and 10 ?m. The waveguides show low losses of ? = 1.38?1.84 cm?1 at a wavelength of 1.3 ?m.