一种具有平顶陡边响应的新型谐振腔增强型(RCE)光电探测器的理论分析及模拟

提出了一种适用于波分复用系统的具有平顶陡边响应的新型谐振腔增强型 (RCE)光电探测器结构 ,模拟得到了量子效率从峰值下降 0 5dB的线宽 1 8nm ,10dB的线宽 5 6nm ,2 0dB的线宽 10 4nm ,量子效率峰值99 7%,几乎没有凹陷的响应曲线。     

一种具有平顶陡边响应的长波长光探测器

在PIN型光探测器的基础上制备了一种适用于波分复用系统的具有平顶陡边响应的长波长光探测器。利用低压金属有机化学气相沉积(LP-MOCVD)设备在GaAs衬底上二次外延生长了具有台阶结构的GaAs/AlGaAs滤波腔和InP基PIN光探测器。高质量的GaAs/InP异质外延采用了低温缓冲层生长工艺;具有台阶结构的Fabry-Pérot(F-P)滤波腔采用了纳米量级台阶的制备方法。通过理论计算优化了实现平顶陡边光谱响应特性的器件结构;并通过实验成功制备出了具有平顶陡边响应性能的光探测器,器件的工作波长位于1 549nm,峰值量子效率大于25%,0.5dB光谱响应线宽为3.9nm,3dB光谱响应线宽为4.2nm,响应速率达到17GHz。     

一种具有平顶陡边响应的InP基长波长可调谐光探测器的设计

在一镜斜置三镜腔型光探测器的基础上提出了一种适用于波分复用系统的具有平顶陡边响应的可调谐光探测器结构.该器件由双半波滤波器结构的滤波腔和具有斜镜结构的吸收腔构成,实现了量子效率与光谱响应线宽间的解耦,具有高响应速度与高量子效率;同时,其光谱响应具有良好的平顶陡边特性和窄的光谱响应线宽,并且具有较大的调谐潜力.     

Fabrication and characterization of 1 550 nm polarization-insensitive semiconductor optical amplifiers

Semiconductor Optical Amplifiers (SOAs) can beused asin-line amplifier ,preamplifier ,optical switch,andwavelength converter in future optical systems[1-3].Po-larization-independent gain,high output power and lowgain ripple are desirable features for most…     

InGaAs-GaAs quantum dots for application in long wavelength (1.3 µm) resonant vertical cavity enhanced devices

Microcavity structures containing InGaAs-GaAs quantum dots (QDs) emitting at 1.3μm at 300 K have been studied. The energy distribution of excitons remains an nonequilibrium one up to room temperature due to high localization energies in these QDs. Carrier relaxation is found to proceed mainly via multiphonon processes. The luminescence emission from QDs in a microcavity exhibits a large spectral splitting of TE and TM components as observed in angle-resolved measurements amounting up to 10 nm for an angle of incidence of 30°. A 1.3 μm vertical cavity enhanced QD photodetector based on a single sheet of QDs is shown to have a quantum efficiency >10%. The ground state electroluminescence of a quantum dot resonant cavity light emitting diode shows no saturation up to 2 kAcm⁻².     

A GaAs-Based MOEMS Tunable RCE Photodetector with Single Cantilever Beam

A GaAs-based micro-opto-electro-mechanical-systems(MOEMS) tunable resonant cavity enhanced(RCE) photodetector with a continuous tuning range of 31nm under a 6V tuning voltage is demonstrated.The single cantilever beam structure is adopted for this MOEMS tunable RCE photodetector.The maximum and minimum peak quantum efficiency during the tuning are 36.9% and 30.8%，respectively.The maximum and minimum full-widthathalf-maximum (FWHM) are 20nm and 14nm，respectively.The dark current density is 7.46A/m2 without bias.     

特殊图案透明欧姆接触微结构提高谐振腔增强型光探测器的响应性能

为解决谐振腔增强型(RCE)光探测器的耦合效率和响应速率的矛盾,提出了采用特殊图案透明欧姆接触的微结构及其制备工艺方案,从而使得在器件入光面积不变的情况下,欧姆接触部分的总面积显著减小,在不影响器件量子效率的前提下达到减小电容、提高响应速率的目的。在台面面积为50μm×50μm的情况下,获得了18 GHz的响应带宽。研制的谐振腔增强型光探测器的响应速率得到了显著的提高。     

谐振腔增强型光探测器的高速响应性能研究

高速长波长光探测器是高速光纤通信系统和网络的关键器件，它要求光探测器具有宽的频率响应带宽和高量子效率。常用的PIN光探测器由于量子效率和高速性能均受到吸收层厚度的牵制，使得二者相互制约，成为一对矛盾。谐振腔增强型(RCE)光探测器为这一矛盾的解决提供了有效的方案。基于谐振腔增强型光探测器的实际设计和制作模型，分析了器件吸收层中的光场分布，并将其运用于载流子的连续方程，从理论上详细地分析了器件的高速响应特性，给出了计算结果。针对研制的高速长波长谐振腔增强型光探测器，进行了理论分析和实际器件测试的结果比较，得到了比较一致的结果。     

单悬臂梁结构的GaAs基MOEMS可调谐RCE光探测器

成功研制了GaAs基MOEMS可调谐RCE光探测器.该器件采用单悬臂梁结构,在6V的小调谐电压下,获得了31nm的连续调谐范围.在调谐过程中,峰值量子效率最大为36.9%,最小为30.8%;FWHM最大为20nm,最小为14nm.在0V偏压下器件的暗电流密度为7.46A/m2.     

Design and fabrication of InP micro-ring resonant detectors

The quantum efficiency and the transient response of the InP semiconductor micro-ring resonant detector are analyzed to get the optimum design parameters.Then the side coupling micro-ring resonant is fabricated using the InP semiconductor material based on the parameters.The micro-ring resonant cavity has the raius of 80 μm,waveguide width of 3 μm and the coupler gap of 1 μm.The test results show that the FSR is 0.75 nm,and the FWHM is 0.5 nm,which are consistent with the theoretical calculation results.     

Design of a tunable GaAs/AlGaAs multiple-quantum-wellresonant-cavity photodetector

We describe a tunable p-i-n photodetector using GaAs/AlGaAs multiple quantum wells (MQW) embedded in a vertical resonant cavity. The structure is similar to that employed for Fabry-Perot MQW modulators and lasers. Turnability is achieved by utilizing the quantum-confined Stark effect. The calculated response predicts a tuning range up to 20 nm. As a dual-channel wavelength-division demultiplexer, the crosstalk ratio is calculated to be <-5 dB for one channel and <-15 dB for the other. The quantum efficiencies are projected to be in the range of 40% to 55%     

A s-band 2.5 mw high power broadband klystron

In this paper, the design considerations of a high-efficiency high-gain broadband klystron are described. Its buncher has been studied by using small signal gain and large signal efficiency programs. With small gain greater than 50’dB, the buncher bandwidths of 10% and 10–15% can be obtained for 7 and 8 cavity klystrons respectively. The design methods and measured results of output circuits of two types are introduced. The bandwidths of the filter type and the overlapping mode two gap cavity output circuits are about 7.5–10% and 10–12% respectively. Two types of S-band broadband klystrons with the two respective output circuits described are constructed and tested, and the one with the former output circuit has 1 dB equi-drive bandwidth of 7.5% with an efficiency of 38% and a gain of 43 dB, while the other with the later output circuit has 1 dB equidrive bandwidth of 10%. Their output power is greater than 2.5 MW.     

新型三腔谐振腔增强型光探测器的理论分析和数值模拟

提出了一种新的谐振腔增强型 (RCE)光探测器结构 ,它将器件结构中的谐振腔分为三个子腔。分析表明 ,采用这种新结构的光探测器在保留了 RCE光探测器优点的同时 ,还实现了器件量子效率及其光谱响应线宽之间制约关系的解耦 ,因而可以同时获得窄的光谱响应线宽 (<1 nm) ,高的量子效率 (>90 % )和高的响应速度。该器件可望在密集波分复用 (DWDM)光通信系统中得到广泛应用     

Narrow band green organic photodiodes for imaging

Accurate color reproduction using image sensors requires four narrow-band absorbing photodetectors (blue, green, yellow and red). Current photodetectors use a broadband photodetector in combination with color filters, which generally do not have sufficient wavelength discrimination for illuminant independent color recognition. We have developed a green-sensitive organic photodetector, in which color selection is achieved using a narrow-absorbing ketocyanine chromophore, coupled with a low finesse electro-optical cavity inducing further spectral narrowing. The optimized device contained a bulk heterojunction light-absorbing layer comprised of a ketocyanine dye blended with [6,6]-phenyl-C₆₁-butyric acid methyl ester. The photodetector had a response full width at half maximum of 80 nm centered around 525 nm, and an external quantum efficiency of 15% at −1.0 V, which is the highest so far reported for a narrow band green-absorbing organic photodetector. The performance of this detector is sufficient to meet the specifications required by machine vision systems.     

背照式InGaN紫外探测器的制备与数值模拟

研究了背照式InGaN p-i-n结构的紫外探测器的制备与数值模拟.通过低压金属有机化学气相沉积(MOCVD)方法生长p-GaN/i-InGaN/n-GaN外延片,采用标准的Ⅲ-Ⅴ族器件制备工艺,成功制备出p-i-n结构的InGaN紫外探测器.探测器台面半径为30 μm,在-5V偏压下暗电流为-6.47×10 1 2 A,对应的电流密度为2.29×10-7 A/cm2.该探测器响应波段为360～380 nm,在371 nm处达到峰值响应率为0.21 A/W,对应的外量子效率为70％,内量子效率为78.4％.零偏压下,优值因子R0A=5.66×107 Ω·cm2,对应的探测率D* =2.34×1013 cm·Hz1/2·W-1.同时,利用Silvaco TCAD软件进行数值模拟,响应率曲线仿真值与实验值拟合较好.     

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。     

A novel high-speed silicon MSM photodetector operating at 830 nmwavelength

A novel high-speed silicon photodetector that operates at a wavelength of 830 nm is reported. It consists of a Metal-Semiconductor-Metal (MSM) detector that is fabricated on a 5-μm thick silicon membrane. The detector has a measured -3 dB bandwidth of 3 GHz at 10 V, which is almost one order of magnitude larger than the reported bandwidth of conventional silicon MSM detectors as measured at 830 nm. The DC responsivity is 0.17 A/W, corresponding to an internal quantum efficiency of 60.5% and an external quantum efficiency of 25.4%. The large bandwidth and good responsivity at the wavelength of interest, combined with its low operating voltage and compatibility with most silicon integrated circuit technologies, make this detector a promising candidate for monolithic optoelectronic receiver circuits for use in short distance optical communication systems and computer interconnects     

Wavelength conversion technique based on self phase modulation in highly nonlinear microstructure fiber

A wavelength converter based on the self phase modulation(SPM) effect in highly nonlinear microstructure fibers(MFs) is proposed.The core diameter and the pitch of the fiber are 2.05 μm and 5.0 μm,respectively,and the diameter of the airholes in the fiber cladding is 4.50 μm.The calculating nonlinear coefficient is 112.2 W-1 km-1 and it is 11 times higher than that of a conventional dispersion-shift fiber and 56 times higher than that of a conventional single-mode fiber.The length of the fiber i...     

A high-efficiency 50 GHz InGaAs multimode waveguide photodetector

A side-illuminated p-i-n photodetector with a multimode waveguide structure is proposed. Numerical and experimental results show that higher-order mode lights greatly enhance the coupling efficiency between the waveguide photodetector (WGPD) and a fiber, which leads to a high external quantum efficiency. The multimode WGPD has the major advantage that the external quantum efficiency and bandwidth can be derived independently of each other because the multimode waveguide structure can be designed without deteriorating electrical properties. The fabricated WGPD has an external quantum efficiency of 56% without AR coating and 68% with AR coating, and an electrical frequency 3 dB greater than 50 GHz at a 1.55-μm wavelength     

一种850 nm单片集成光接收机前端

采用0.5μm GaAs PHEMT工艺和台面光刻互连工艺研制了一种850nm光接收机前端单片电路,包括金属-半导体-金属光探测器和跨阻前置放大器。探测器光敏面积约2000μm2,电容小于0.15pF,4V偏压下的暗电流小于14nA。跨阻前置放大器-3dB带宽接近10GHz,跨阻增益约43dBΩ。光接收机前端在输入2.5Gb/s非归零伪随机二进制序列调制的850nm光信号下得到较为清晰的输出眼图。