共查询到20条相似文献,搜索用时 9 毫秒
1.
An optical holographic backplane interconnect system capable of high-speed information transmission between optoelectronic transmitter/receiver boards is described. Using conjugate pairs of transmission gratings in a folded reflection geometry, a practical method of insulating the interconnect system from wavelength variations due to temperature or power fluctuations can be achieved. The final demonstration unit was developed in a fully packaged form and has the potential for reconfigurable interconnects and may serve as a testbed for a variety of interconnect networks and hardware protocols 相似文献
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Shiragaki T. Fujiwara M. Suzuki S. Burke C. Shiozawa T. 《Lightwave Technology, Journal of》1994,12(8):1490-1496
This paper presents, for potential application to network failure restoration, an optical digital cross-connect system (DCS) which uses both a photonic switching network and an electric DCS. It is shown that a system constructed of LiNbO3 8×8 switch matrices and semiconductor traveling-wave optical amplifiers (TWA's) could be applied to metropolitan area networks. An experimental optical DCS system has been designed and fabricated which incorporates both LiNbO3 switch matrices and TWA's, and with it, line-failure restoration, a fundamental operation of optical DCS, has been successfully demonstrated 相似文献
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Jackson S.M. Reed G.T. Tang C.K. Evans A.G.R. Clark J. Aveyard C. Namavar F. 《Lightwave Technology, Journal of》1997,15(12):2259-2263
A device has been designed and fabricated to demonstrate the principle of using the interference pattern of a number of coherent optical sources to form and steer an optical beam. Steering of the beam can be accomplished by varying the relative phase of the constituent sources. The effect of relative source phase variation and source separation variation has beers considered and optimized using a multiple source interference model. In this case the constituent sources are the outputs of integrated optical waveguides, excited by a common optical source to maintain relative coherence. In order to demonstrate the principle of beamsteering, a device with two constituent sources (waveguides) has been fabricated, and the resultant output interference pattern has been laterally translated by varying the phase of the output of one waveguide with respect to the other, via a novel optical phase modulator 相似文献
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A new, simple method of optically implementing optical parallel logic gates has been described. Optical parallel logic gates can be implemented by using a lensless shadow-casting system with a light-emitting diode (LED) array as a light source. Pattern logic, i.e., parallel logic for two binary patterns (variables), is simply obtained with these gates; this logic describes a complete set of logical operations on a large array of binary variables in parallel. Coding methods for input images are considered. Applications of the method for a parallel shift operation and optical digital image processing, processing of gray-level images, and parallel operations of addition and subtraction for two binary variables are presented. Comparison of the operation of the proposed optical logic gate with that of array logic in digital electronics leads to a design concept for an optical parallel array logic system available for optical parallel digital computing. 相似文献
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High-speed electrical data transmission through low-cost backplanes is a particularly challenging problem. We present for the first time a very effective approach that uses the concept of duobinary signaling to accomplish this task. Using a finite-impulse-response filter, we are able to compensate for the phase and amplitude response of the backplane such that the resulting frequency response of the channel is that of an ideal duobinary filter. At the output of the backplane, we use an innovative pseudodigital circuit to convert the electrical duobinary to binary. For 10-Gb/s data transmission, we demonstrate a bit error rate <10/sup -13/ through electrical backplane traces up to 34 in in length on FR4. A full discussion of the concept, system architecture, and measured results are presented. Analysis is presented that compares and contrasts this approach to PAM-4 and standard nonreturn-to-zero signaling. 相似文献
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A guided-wave optical backplane bus system intended for use in high-performance board-to-board interconnects is described. Its multiplexed polymeric holograms can implement optical signal broadcast between boards so that all boards share common optical channels. By introducing an active coupler to the doubly multiplexed hologram at the center board, signals received from any board can be rebroadcast to all other boards. We describe the design concepts for a centralized optical backplane and the resulting performance and assembly advantages over previously developed guided-wave and free-space optical backplane bus systems used for broadcasting signals. These advantages include equalized fan-out power, increased interconnect distance, and simpler fabrication 相似文献
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We report for the first time a bidirectional optical backplane bus for a high performance system containing nine multi-chip module (MCM) boards, operating at 632.8 and 1300 nm. The backplane bus reported here employs arrays of multiplexed polymer-based waveguide holograms in conjunction with a waveguiding plate, within which 16 substrate guided waves for 72 (8×9) cascaded fanouts, are generated. Data transfer of 1.2 Gbt/s at 1.3-μm wavelength is demonstrated for a single bus line with 72 cascaded fanouts. Packaging-related issues such as transceiver size and misalignment are embarked upon to provide a reliable system with a wide bandwidth coverage. Theoretical treatment to minimize intensity fluctuations among the nine modules in both directions is further presented and an optimum design rule is provided. The backplane bus demonstrated, is for general-purpose and therefore compatible with such IEEE standardized buses as VMEbus, Futurebus and FASTBUS, and can function as a backplane bus in existing computing environments 相似文献
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The amplification characteristics of the distributed-feedback (DFB) laser amplifier are studied. The amplifier has a narrow, single-frequency gain-bandwidth product and the maximum-gain frequency tunability. With these advantages, the amplifier can be applied as an optical narrowband filter. This filter has optical frequency selectivity with an extinction ratio of better than -15 dB for optical inputs separated by 9.8 GHz having different optical input powers. By using a multielectrode DFB laser amplifier, the wide-range tunability of a gain maximum frequency (33.3 GHz) can be obtained while maintaining a constant gain and a constant gain-bandwidth product. Optical frequency selection with an extinction ratio of better then -20 dB can be obtained for two optical inputs separated by 15.4 GHz and having the same input power 相似文献
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A multichip module of an optical transmitter, which consists of flip-chip bonded 1/spl times/4 VCSELs on a CMOS driver array IC, is fabricated and demonstrated. The -3 dB bandwidth and adjacent crosstalk of the hybrid integration multichip module are about 4.5 GHz and less than -30 dB, respectively. The whole integrated multichip volume is 1.1/spl times/1.2/spl times/0.52 mm/sup 3/ for four channels. 相似文献
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为了解决红外变焦系统短焦部分冷反射严重的问题,提出了一种双孔径设计方法,设计了一种双孔径红外变焦光学系统。系统工作波段为中波3.7 ~4.8 m,焦距为30/150/300 mm,10变倍比,具有100%冷光阑效率。对双孔径系统的短焦部分和单孔径系统短焦部分的冷反射强度进行了对比分析,双孔径系统的冷反射得到有效控制。双孔径红外变焦光学系统具有像质好、变倍比大、短焦冷反射小、结构紧凑的特点,可使大变倍比的红外变焦光学系统在红外成像系统中得到广泛应用。 相似文献
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基于Lamber -Beer定律 ,利用波长为 1.3 3 μm的脉冲lnP/InGaAsP半导体激光器作为测量光源 ,用低损耗的光纤进行光信号的传输并以钽酸锂热释电探测器作光电转换器件 ,设计出了一种新颍的远距离监测甲烷浓度的光纤传感系统。以此光纤传感系统为探头 ,设计出了一种可实时监测甲烷浓度的仪器 ,并能实现 3km的远距离遥测。介绍了该光纤传感系统及由该光纤传感系统构成的监测仪器的基本结构与工作原理 ,讨论了其中的技术难点及其相应的解决方法 ,并给出了监测仪器相应的技术指标 相似文献
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An optical backplane for high-speed data transmission was experimentally examined. The transmission of 2.5 Gbit/s per channel over a 1 m multimode polymer waveguide is demonstrated 相似文献
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Optical preamplifier using optical modulation of amplified spontaneous emission in saturated semiconductor optical amplifier 总被引:1,自引:0,他引:1
This paper demonstrates a novel optical preamplifier using optical modulation of amplified spontaneous emission (ASE) emitted from a saturated semiconductor optical amplifier (SOA). Requirements on optical alignments and antireflection coating for SOAs can be relaxed and the elimination of an optical filter gives us a large tolerance of an input light wavelength in the proposed optical preamplifier. A small-signal gain of a fabricated preamplifier was over 13.5 dB for an input power of below -20 dBm. An optical gain bandwidth was over 60 nm. We measured the small-signal response of the optically modulated ASE. The 3 dB bandwidths at SOA bias currents of 200, 300, and 400 mA were 5.8, 12.6, and 16.5 GHz, respectively. We also investigated improvements in receiver sensitivities with the proposed optical preamplifier. Our calculation shows a possibility of 10 dB improvement in receiver sensitivities by using the optical preamplifier at 10 Gb/s. The measured receiver sensitivity was -22.7 dBm at 10 Gb/s with the optical preamplifier, which is corresponding to an improvement of 2.5 dB in the receiver sensitivity. Further improvements of the receiver sensitivity can be expected by optimizing the structure of SOAs for saturating ASE. 相似文献
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H. Keller M. Glade B. Hartl C. Horbach 《International Journal of Communication Systems》1993,6(3):143-149
Within the framework of the ‘FITL (fibre in the loop) evolution’, Siemens is developing a prototype based on a passive optical network (PON) for the economic provision of BISDN services in the subscriber access area. It provides 32 subscribers with BISDN access up to a maximum user data rate of 45 Mbit/s per subscriber. The information is transferred via ATM cells and PON-specific overhead in both directions on the PON at a data rate of 155.52 Mbit/s. For transmission to the subscribers, the time division multiplex procedure (TDM) is used. For transmission in the opposite direction, a highly flexible time division multiple access procedure (TDMA) controls the access to PON for the subscriber-side line terminations. In order to keep the transmission system inexpensive emphasis is placed on a digital calibration of the fibre loop delay, a burst transmitter at the subscriber side without amplitude recovery and a burst receiver at the exchange side with purely digital bit synchronization. However, to achieve these features a small part of data rate must be used as a PON specific overhead. 相似文献
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T. Yamatoya F. Koyama 《Photonics Technology Letters, IEEE》2003,15(8):1047-1049
We fabricated an antireflection (AR)-coating-free semiconductor optical amplifier (SOA) with an absorbing region for an optical preamplifier. In the fabricated SOA, the resonance of light was fully suppressed so that the amplitude of the ripple of amplified spontaneous emission (ASE) spectra was as small as 0.36 dB, which is comparable to conventional SOAs with AR coating at both facets. We formed an optical preamplifier using the AR-coating-free SOA. The gain saturation of the SOA gives us the signal conversion to ASE and the amplification of the signal. The small-signal fiber-to-fiber and chip gain of the preamplifier were 11.4 and 20.0 dB, respectively. The 3-dB optical gain bandwidth of the preamplifier was about 30 nm. 相似文献
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In this paper, a novel multiple slot loading technique is studied in detail for the isolation enhancement of the dual‐band MIMO antenna system. The proposed MIMO antenna design consists of the microstrip patch loaded with T‐shaped slots parallel to the non‐radiating edge of the patch. The frequency tuning could be achieved by varying the length of the T‐shape slot arm. The proposed MIMO antenna system is optimised for operation in WLAN and WiMAX applications. The isolation enhancement is achieved by providing simple multiple slots loaded in the ground plane between radiating elements. The length of the slots is λ/4 . The system is fabricated and tested using a vector network analyser and anechoic chamber. The reduction in mutual coupling up to ?29.16 dB and ?24.09 dB for the 2.4 GHz and 3.4 GHz, respectively, is achieved. The bandwidths are 62.3 MHz (3.33–3.39 GHz) and 55.5 MHz (2.37–2.42 GHz), respectively. The total gain obtained in this case is 1.8 dBi at 2.4 GHz and 1.2 dBi at 3.4 GHz, respectively. The dimensions of the proposed designed antenna are 70 mm × 60 mm × 1.6 mm. The results were also verified through mutual coupling parameters like envelope correlation coefficient (ECC) and channel capacity loss (CCL) at the desired frequencies. 相似文献