用于高速GaAs IC在片检测的电光取样系统

目前直接电光取样技术是在片检测砷化镓高速集成电路内部动态特性的最好方法。我们建立了半导体激光器电光取样系统，测试了梳状信号发生器输出的４３．７ｐｓ的电脉冲信号以及频率５ＧＨｚ的微波信号，并测试了频率３ＧＨｚ的微波信号的位相移动或时间延迟以及铁氧体微波移相器的静态特性曲线，这个系统将被应用于砷化镓高速集成电路内部动态特性在片检测。     

Electro-optic sampling of fast electrical signals using an InGaAsP injection laser

We demonstrate a new electro-optic sampling system for the measurements of fast electrical waveforms at gigahertz repetition rates. The system uses a mode-locked InGaAsP injection laser as a source of sampling pulses and employs the electro-optic effect in the GaAs substrate of a microstrip line.     

电光取样技术在ps级超短电脉冲测量和GHz高频电信号测量中的应用

对ps级超短电脉冲测量而言,电光取样是目前最准确、最有效的方法之一。本文介绍了电光取样的基本测量原理及实验途径,对测量的误差因素进行了分析。电光取样对由电光晶体如GaAs、LiNbO_3等制成的光电器件的瞬态响应测量具有特殊优点。本文着重对GaAs集成电路的瞬态测量原理和方法及误差因素进行了介绍。电光取样基于谐波混频原理对GaAs高频场分布的测量也十分有效。     

Direct electro-optic sampling of a GaAs integrated circuit using a gain-switched InGaAsP injection laser

We demonstrate an electro-optic sampling system based on a gain-switched InGaAsP injection laser. The system has a temporal resolution of 18ps and is used for noninvasive probing of waveform internal to a GaAs monolithic integrated circuit operating at 2.4GHz.     

Direct electro-optic sampling of transmission-line signals propagating on a GaAs substrate

We report a new picosecond electro-optic sampling probe suitable for noncontact electronic characterisation of high-speed monolithic GaAs integrated circuits.     

Frequency response of an internal amplifier in a high-speedintegrated circuit measured by electro-optic sampling

The frequency response of an FET amplifier within a high-speed GaAs integrated circuit has been measured directly using ultrashort optical pulses from a gain-switched GaInAsP injection laser and the electro-optic sampling technique. The 3 dB bandwidth for the FET amplifier is 4-4.5 GHz     

Electro-optic sampling using an external GaAs probe tip

The first laser-diode-based external electro-optic (EO) sampling using a GaAs probe tip is described. This tip is a longitudinal electric field sensor, being therefore immune from optical crosstalk. The minimum detectable voltage is 16 mV/ square root (Hz). The EO sampling is compared with that of a conventional electrical sampling oscilloscope, and the two are shown to be in excellent agreement.<>     

Strain-induced optical waveguiding in GaAs epitaxial layers at 1.15 ?m

Transverse optical waveguide modes have been observed in GaAs Schottky-barrier electro-optic waveguide modulators with no electrical bias. This is attributed to the spatial variation of the dielectric constant generated by stresses originating in the metal Schottky-barrier stripe.     

Picosecond electro-optic probing of high-speed integrated circuits using external GaAs tip

External electro-optic sampling has been demonstrated on high-speed integrated circuits using a pulse-compressed mode-locked Nd:YAG laser and a sophisticated GaAs probe tip. The measurement at frequencies up to 40 GHz has been successfully performed with excellent voltage sensitivity of less than 3 mV/ square root (Hz).<>     

Electro-optic sampling with picosecond resolution

The development of an electro-optic sampling system with resolution of better than 2 picoseconds and shot noise limited sensitivity of 11 ?V/?Hz is reported. This system has been used to characterise GaAs photodiodes which have exhibited pulsewidths as short as 5.4 picoseconds (full-width-half-maximum).     

Electro-optic sampling of optoelectronically phase-locked 10.0 GHz microwave signals using semiconductor laser diodes

10.0 GHz microwave signals optoelectronically phase locked by a laser-diode-based GaAs:Cr photoconductive harmonic mixer ( lambda =0.81 mu m) have been measured noninvasively using the electro-optic sampling technique with a gain-switched InGaAsP laser diode ( lambda =1.3 mu m).<>     

Electro-optic imagery of high-voltage GaAs photoconductive switches

We present electro-optic images of GaAs high-voltage photoconductive switches utilizing the electro-optic effect of the semi-insulating GaAs substrate. Experimental methodology for obtaining the images is described along with a self-calibrating data reduction algorithm. Use of the technique for observing fabrication defects is shown     

Millimetre-wave active probe frequency-multiplier for on-wafer characterisation of GaAs devices and ICs

A millimetre-wave active probe quintupler with an output frequency range of 60 to 100 GHz has been developed. The frequency multiplier circuit was implemented in a coplanar waveguide. Using this probe along with the electro-optic sampling technique, on-wafer millimetre-wave vector measurement up to 100 GHz and time-waveform measurement at 77 GHz of test structures on a GaAs substrate have been demonstrated.<>     

Measurement of on-chip waveforms and pulse propagation in digital GaAs integrated circuits by picosecond electro-optic sampling

We demonstrate precise measurement of sub-100 ps rise time on-chip electrical waveforms and of pulse propagation in digital GaAs integrated circuits with the use of picosecond electro-optic sampling. These experiments yield the first non-invasive measurement of single-gate propagation delays via direct and precise observation of on-chip waveforms at the input and output of individual logic gates internal to an integrated circuit.     

Integration of GaAS MESFET drivers with GaAs directional-coupler electro-optic modulators

We demonstrate the first integration of active electronic devices with semiconductor waveguide modulators. By combining ion-implanted GaAs MESFET amplifiers with directional-coupler electro-optic modulators, the DC drive voltage has been reduced by a factor of ?v = 9, making an effective electro-optic figure-of-merit ?vn3r41 for GaAs superior to that of LiNbO3     

Gigahertz logic based on InP metal-insulator-semiconductor field-effect transistors by vapor phase epitaxy

We report a high-speed inverter circuit based on novel enhancement-mode InP metal-insulator-semiconductor field-effect transistors. The devices exhibit an extrinsic transconductance as high as 320 mS/mm at room temperature. Utilizing electro-optic sampling we have measured the propagation delay of the field-effect transistors to be as short as 15 ps/stage at room temperature. These are the highest transconductance and the shortest propagation delay measured with a field-effect transistor on an In-P substrate. Furthermore, the propagation delay measured in this work is comparable to those obtained with GaAs/AIGaAs selectively doped heterojunction transistors at similar temperature.     

Metal-Coated &lt;100&gt;-Cut GaAs Coupled to Tapered Parallel-Plate Waveguide for Cherenkov-Phase-Matched Terahertz Detection: Influence of Crystal Thickness

The influence of crystal thickness of metal-coated <100>-cut GaAs (M-G-M) on Cherenkov-phase-matched terahertz (THz) pulse detection was studied. The M-G-M detectors were utilized in conjunction with a metallic tapered parallel-plate waveguide (TPPWG). Polarization-sensitive measurements were carried out to exemplify the efficacy of GaAs in detecting transverse magnetic (TM)- and transverse electric (TE)-polarized THz waves. The reduction of GaAs’ thickness increased the THz amplitude spectra of the detected TM-polarized THz electro-optic (EO) signal due to enhanced electric field associated with a more tightly-focused and well-concentrated THz radiation on the thinner M-G-M. The higher-fluence THz beam coupled to the thinner M-G-M improved the integrated intensity of the detected THz amplitude spectrum. This trend was not observed for TE-polarized THz waves, wherein the integrated intensities were almost comparable. Nevertheless, good agreement of spectral line shapes of the superposed TM- and TE-polarized THz-EO signals with that of elliptically polarized THz-EO signal demonstrates excellent polarization-resolved detection capabilities of M-G-M via Cherenkov-phase-matched EO sampling technique.     

First 8*8 semiconductor optical matrix switches using GaAs/AlGaAs electro-optic guided-wave directional couplers

Monolithically integrated 8*8 semiconductor optical matrix switches have been successfully fabricated for the first time. They were constructed on GaAs from 64 GaAs/AlGaAs electro-optic directional couplers using a simplified tree architecture. The devices have a chip size of 26.5*3 mm/sup 2/ and a minimum total loss (excluding coupling loss) of 8.7 dB.<>     

Picosecond pulse propagation on coplanar striplines fabricated onlossy semiconductor substrates: modeling and experiments

A simple model for the propagation of high-frequency signals on coplanar striplines with lossy semiconductor substrates is proposed and demonstrated. This model incorporates the effect of a conductive substrate through the loss tangent in a distributed-circuit analysis extended to high frequencies. Very strong attenuation and dispersion due to the substrate are observed even when the GaAs conductance is only 1 mho/cm, corresponding to a doping density of around 10¹⁵ cm ^-3. The accuracy of this model is tested with a direct comparison to experimental data of picosecond pulse propagation on a doped GaAs coplanar stripline (CPS) measured in the time domain using the electro-optic (EO) sampling technique. Good agreement is found in terms of the attenuation and phase velocity of the distorted pulses at four propagation distances up to 300 μm. The pulse propagation on a multiple modulation-doped layer is also studied experimentally as a prototype of high-frequency signal propagation on the gate of a modulation-doped field-effect transistor (MODFET). The attenuation shows linear frequency dependence up to 1.0 THz, contrary to the cubic or quadratic dependence of coplanar transmission lines on low-loss substrates     

GaAs量子阱的能级分析

通过用Numerov方法求解Schrdinger方程计算了GsAs量子阱内的能级和波函数,详细地讨论了能级对各种参数包括阱宽、势垒高度和外加电场的依赖关系。这些结果有助于GaAs/AlGaAs量子阱结构的光电性质研究和器件设计。