Integrated optical receiver with beam localisation

The performance of optical receivers is degraded by misalignment and defocusing of the incident light beam on a detector. The presented integrated optical receiver solves the alignment and defocusing problem using optoelectronic light beam localisation. A demonstrator is realised in a standard CMOS technology     

Integrated PINFET optical receiver with high-frequency InP-MISFET

Monolithic integration of an InGaAsP PIN photodiode with an n-channel enhancement InP-MISFET is reported. Photo-current amplification characteristics at 1000 Mbit/s have been achieved.     

用于计算机光互连的集成化发送器和接收器

从对计算机光互连的实用要求出发，实现了用集成化的发送器和接收器经光纤连接器组成收发对后，能很好地在４×４多处理机系统内用光互连代替电互连。着重探讨了发送器和接收器的结构、设计，以及工艺改进途径，对互连器件的配套选择、性能测试作了一定工作，使之能方便使用。     

Integrated DTMF receiver

A single integrated-circuit receiver for telephone systems is described. A new detection algorithm allows for the proper detection of tones with exceptional insensitivity to speech.     

Integrated optical waveguide polarizer on glass with a birefringentpolymer overlay

An integrated optical waveguide polarizer on glass is described. It is based on a filtering zone propagating only TE mode whereas the TM mode leaks out into a birefringent polymer simply deposited on the glass. The polymer is poled by a corona process. The measured polarization extinction ratio between TE and TM modes is better than 39 dB and the excess loss due to the filtering zone is less than 4 dB. The total loss is in the order of 7 dB     

High-sensitivity receiver optical preamplifiers

High-receiver sensitivities of -40.9, -44.3, -46.2, -49.0, and -51.3 dBm are reported at 2.4, 1.8, 1.2, 0.62, and 0.14 Gb/s, respectively, using a low-noise, 980-nm diode-pumped, erbium fiber amplifier in the receiver preamplifier configuration with all field usable components. This corresponds to a best sensitivity of 156 photons/bit at the input of the optical amplifier (96 photons/bit at the input of the erbium-doped fiber). Selection of a low-chirp laser-diode transmitter, an optical filter with a bandwidth appropriate for filtering the signal, and a low-noise electrical amplifier with appropriate bandwidth in the post detection stage are all critical to achieve very high-receiver sensitivities     

Microwave-bandwidth optical receiver systems

A theoretical and experimental evaluation of optical communications systems capable of microwave bandwidths is presented. The optical transmitter, modulator, and detection techniques are discussed with respect to both direct-detection and optical heterodyne receivers, and experiments in a nonlaboratory environment are described. At the high optical power levels or photon rates which are fundamentally necessary for gigahertz instantaneous bandwidths, it is found that signal-shot-noise limited operation may be obtained with new wideband photodetectors incorporating internal gain. Direct-detection receivers are thus generally superior to heterodyne receivers in these systems. A comparison is made of the relative merits of alternative systems and their dependence on various parameters such as information capacity, range, and background illumination.     

Low-noise optical receiver for high-speed optical transmission

This paper describes the design of a low-noise optical receiver using Si bipolar transistors for high-speed optical transmission. The conventional common emitter-common collector circuit (CE-CC pair) and Darlingtou circuit (transimpedance amplifiers with parallel feedback) are studied. Optimal CE-CC pair collector-biasing current for attaining minimum noise current with a 400-MHz bandwidth is 2.7 mA, and less than 1.2 mA for the Darlington circuit. It is confirmed that the Darlington circuit is better than the CE-CC pair in signal-to-noise ratio by about 1.5 dB. The low-noise Darlington optical receiver with a Ge-avalanche photodiode has achieved an optical sensitivity of -41 dBm for a 400 Mbit/s RZ pulse with a bit error rate of 10^-10. This is a 2.5-dB improvement in optical sensitivity over that of the conventional CE-CC receiver.     

Low-noise optical receiver for high-speed optical transmission

This paper describes the design of a low-noise optical receiver using Si bipolar transistors for high-speed optical transmission. The conventional common emitter-common collector circuit (CE-CC pair) and Darlington circuit (transimpedance amplifiers with parallel feedback) are studied. Optimal CE-CC pair collector-biasing current for attaining minimum noise current with a 400-MHz bandwidth is 2.7 mA, and less than 1.2 mA for the Darlington circuit. It is confirmed that the Darlington circuit is better than the CE-CC pair in signal-to-noise ratio by about 1.5 dB. The low-noise Darlington optical receiver with a Ge-avalanche photodiode has achieved an optical sensitiyity of -41 dBm for a 400 Mbit/s RZ pulse with a bit error rate of 10^-10. This is a 2.5-dB improvement in optical sensitivity over that of the conventional CE-CC receiver.     

Polarization independent coherent optical receiver

This paper describes an optical heterodyne receiver for DPSK signals which can receive an optical signal having an arbitrary polarization state. This is achieved by splitting the received signal between two orthogonal polarization axes and processing the resulting two signals as in a conventional DPSK heterodyne receiver. The sum of the two demodulated signals provides a baseband signal independent of the polarization state of the received optical signal. When the receiver noise is dominated by the shot noise of the photodetectors, the receiver provides a BER of 10^-9for an average number of 22 photon/bit. In comparison, a conventional optical heterodyne receiver requires under the same noise condition 20 photon/bit to achieve the same BER for a received optical signal polarized along the polarization axis of the local optical signal.     

一款应用于FTTH的CATV光接收机的设计

在分析国内外FTTH光接收机应用前景的基础上,设计并实现了一款应用于FTTH的CATV光接收机.在低动态接收、高灵敏度和成本方面有较大突破,光功率接收范围达到-8～0dBm,功耗降低到约3W,制造成本降低到300元左右,具有很好的实用价值.     

光通信用光接收机技术及其进展

光接收机是光纤通信系统的重要组成部分,它的作用是将由光纤传来的微弱光信号转换为电信号,经放大、处理后恢复原信号.光接收机的性能对整个系统的通信质量有很大的影响.从不同的角度对光接收机进行了分类,进而分析了光接收机技术的最新进展,最后对光接收机技术的发展进行了展望.     

无前导字节的突发模式光接收机探讨

无前导字节的突发模式光接收机在系统兼容性和提高传输效率方面相对于传统的有前导字节的突发模式光接收机有很大的优越性.本文在理论上给出了突发模式光接收机的误码率公式,分析了不用前导字节对接收机性能的影响.     

Gigabit receiver ICs for optical communications

The authors discuss gigabit receiver ICs for optical communications, focusing on their circuit and package design, the performance of receivers that were fabricated, and their application to a 1.6 Gb/s optical receiver. The key technologies for the receivers are discussed, and a design based on these key technologies is proposed. The proposed design is used to fabricate six receiver ICs (eight chips) using an ultra-high-speed bipolar process with transistors having a unity gain bandwidth of 6-8 GHz. The receivers are suitable for long-haul optical transmission at bit rates up to 1.6 Gb/s. Experimental results show that the 1.6 Gb/s receiver has an optical dynamic range of more than 23 dB without any adjustment, and the received average optical power required to maintain a 10^-11 error rate is less the -31 dBm     

Integrated optical circuits

Research on optical communication systems indicates the future need for a compact, rugged, and economical medium for circuit realization. Encapsulated planar arrays of rectangular dielectric waveguides are attractive for this purpose. The individual guides would have dimensions on the order of a few micrometers while the planar arrays might cover an area of a few square centimeters. Integrated circuit technology appears adaptable to batch processing such circuits. Recent theoretical and experimental results are surveyed which support this viewpoint.     

EPON光接收灵敏度研究

结合IEEE 802.3 ah标准中的以太无源光网络(EPON)接收灵敏度指标,着重分析了接收灵敏度光调制幅度(OMA),该OMA指标的采用有利于系统降低对消光比的要求,使发射机和接收机的设计更加简单;最后,简要讨论了OMA和增强型接收灵敏度的测试,指出增强型测试更有实际意义。     

Integrated optical interconnections

The use of optical interconnections between processors, boards, chips, and gates in electronic digital systems to overcome the current performance limitations is described. The advantages of optical interconnections in relation to the interconnection distance, the data capacity, and the interconnection functions are presented. The devices which will support practical implementation of optical interconnections and the integration of optical interconnection devices are discussed. The development of future integrated optoelectronic materials, processing, and fabrication technologies to support integrated optical electronics is also discussed     

Ultra-low-noise and wideband-tuned optical receiver synthesis anddesign

A new general optical receiver design method based on the synthesis of optimum noise-matching networks is presented. It is based on the noise figure concept in conjunction with broadband matching theory. The design is accurate because it directly utilizes the active device noise parameters, such as minimum noise figure, noise resistance, and optimum source impedance, which are readily available at microwave frequencies. The analysis has established the general noise-matching requirements of the tuning network that result in the minimum obtainable equivalent input noise current and the fundamental noise limit in tuned receivers. Synthesis procedures are described that can closely satisfy the general noise-matching requirements, which has led to a new low pass filter-type matching network with ultra-broadband characteristics that also approach the fundamental noise limit. The design principles are verified, with an experimental 10 Gb/s PIN-HEMT optical receiver that demonstrates a bandwidth of 6.3 GHz with a gain flatness of ±0.8 dB over the entire frequency range and a measured average noise current of 5 pA/√(Hz)     

一种抗辐照的光电探测芯片设计

光电耦合器的核心模块是光电探测芯片。介绍了一种抗辐照光电探测芯片的设计,该电路基于0.5 μm标准互补金属氧化物半导体(CMOS)工艺研制,内部包含跨阻放大器(TIA)、基准源和比较器等模块电路,并通过电路结构和版图设计进行抗辐照加固。测试结果表明,抗总剂量能力达到200 krad(Si),同时,该芯片数据传输速率可达10 MBd,其输入高电流范围为6~18 mA。     

Single-channel imaging receiver for optical wireless communications

A novel and simple single-channel imaging receiver for high-speed portable wireless infrared communications is proposed. The receiver is able to aim automatically at the ceiling areas with better signal-to-noise ratio. The self-orienting capability, together with the very narrow field of view employed, drastically reduces the path loss, background noise and multipath distortion. Moreover, its single-channel structure minimizes hardware complexity in contrast to conventional angle diversity receivers. Our simulation results indicate that the proposed receiver, operating in a multispot diffusing configuration, offers significant gains in power requirements and channel bandwidth compared to angle diversity receivers.