应用于塑料光纤系统的LED的温度特性及其补偿

本文介绍了塑料光纤系统的特点,光源和探测器的温度特性以及温度补偿方法,并指出塑料光纤系统是当前传输距离50米以内应用最活跃的光通信系统和光纤传感器系统。     

Optical Implementation of CMOS/SEED Optoelectronic Integrated Crossbar Interconnection Network

１　Ｉｎｔｒｏｄｕｃｔｉｏｎ　　Ａｓ“ｗｉｒｅｉｎｔｅｒｃｏｎｎｅｃｔｉｏｎ”ｏｆｅｌｅｃｔｒｏｎｉｃｃｏｍｐｕｔｅｒｈａｓｓｏｍｅｓｈｏｒｔａｇｅｓｓｕｃｈａｓｂｏｔｔｌｅｎｅｃｋ,ｃｌｏｃｋｓｋｅｗ,ＲＣｃｏｎｓｔａｎｔ,ｌｉｍｉｔｅｄｔｉｍｅｓｐａｃｅｐｒｏｄｕｃｔ,ｃｒｏｓｓｔａｌｋ,ｉｔｉｓｄｉｆｆｉｃｕｌｔｔｏｆｕｒｔｈｅｒｉｍｐｒｏｖｅｔｈｅｐｅｒｆｏｒｍａｎｃｅｏｆｅｌｅｃｔｒｏｎｉｃｉｎｔｅｒｃｏｎｎｅｃｔｉｏｎｎｅｔｗｏｒｋ．Ａｓｌｉｇｈｔｗａｖｅｈａｓｔｈｅｆｅａｔｕｒｅ…     

Optical Implementation of CMOS/SEED Optoelectronic Integrated Crossbar Interconnection Network

An optical implementation of CMOS/SEED optoelectronic integrated crossbar interconnection network is reported. The CMOS/SEED smart pixel arrays with O/E light windows are used as logical controlling switch nodes. High/lower modulating ratio of the output light density is about 1.4. The light beam is supplied by a 0.85 μm semiconductor laser diode. 8×2 spot arrays formed by a computer-generated phase grating are used as the pumping light beams for CMOS/SEED light modulators. High-precision 2-D optical fiber bundle arrays are used as the I/O access devices. 16×16 optical crossbar interconnection network is realized using our experimental setup. It is easy to couple with CMOS/SEED smart pixel arrays by using 2-D optical fiber bundle arrays as the I/O access devices. Compact in comparison with other optical interconnection systems.     

基于LabVIEW的多点串联光纤传感系统设计

设计了一种远程多点光纤传感系统用于大范围对象测量,其结构为一个本地控制节点通过双向光纤链路串联所有远端传感节点。在本地控制节点共享光源、光电检测器等光电器件,并结合虚拟仪器实现数据处理电路;而远端传感节点仅包含敏感元件、无源光器件构成的光路,并能直接实现时分复用。以3节点系统的甲烷气体检测为例进行实验和计算,结果证明该方案能够有效工作,通过循环检测可使首个传感节点的相对误差降至0．2％以下。     

Low-Temperature Radiometric Measurements Using a Silver Halide Optical Fiber and Infrared Optical Devices

In this study, we measured an infrared radiation which is transferred by a silver halide optical fiber from a heat source using a radiometer system for low-temperature measurements. To increase the amount of infrared radiation through the silver halide optical fiber and to the pyroelectric sensor, infrared optical devices used were an infrared focusing lens and a collimator. The relationship between the temperatures of a heat source and the measured radiometer signals were determined. The measurable temperature range of a fiber-optic temperature sensor using a pyroelectric sensor was from 298 to 333 K. It is expected that a noncontact low-temperature sensor using an infrared optical fiber can be developed for medical and industrial usages based on the results of this study.     

纤维光锥有效透过率的理论分析

光锥的有效透过率不仅影响光锥与CCD的耦合效率,而且会影响到耦合器件的信噪比.本文主要从理论上讨论了影响光锥有效透过率性能的因素,从纤维光学元件的实际内部结构推导出了其实际有效填充率,从光线在光锥中的传输特征推导出了光线在光锥中传播时产生的衰减损耗,最后提出了提高光锥有效透过率的方法和途径.     

Performance investigation of microphotonic-silicon devices in a field-trial all-optical network

The performance of microphotonic-silicon devices in a geographically-distributed optical fiber network is experimentally investigated. Two different devices are tested: an optical filter based on a silicon ring resonator and an all-optical wavelength converter based on four-wave mixing in a dispersion-tailored highly nonlinear silicon waveguide. The evaluation of the devices is performed by means of eye diagrams and measurements of the bit error rate.     

Improved design for SOI based evanescently coupled multilayer spot-size converter

We report an improved version of a spot-size converter (SSC) consisting of a silicon nanowire evanescently coupled to a phase-matched Poly-Si multilayer structure. With wider transversal dimensions the multilayer structure expands the mode significantly thus increasing the coupling efficiency with the conventional single-mode fiber. Detailed optimization process of a 17-layer based SSC is discussed and its coupling efficiency with a high-NA fiber of radius 2 μm is obtained as 98% providing only 0.087 dB loss. Vertical alignment tolerance between the optimized SSC and a high-NA fiber of radius 2 μm is also shown. This novel design does not consist of a taper and can be fabricated by using CMOS compatible process. It has a short device length and more relaxed alignment tolerances with the fiber. Full-vectorial and computationally efficient finite element method and the least squares boundary residual method have been used for the analysis and optimization of the proposed structure.     

Optical fiber modulator derivates from hollow optical fiber with suspended core

A fiber optic integrated modulation-depth-tunable modulator based on a type of hollow optical fiber with suspended core is proposed and investigated. We synthesized magnetic fluid containing superparamagnetic Fe(3)O(4) nanoparticles and encapsulated it in the hollow optical fiber as the cladding layer of the suspended core by fusing the hollow optical fiber with the multimode optical fibers. The light with a wavelength of 632.8 nm is coupled in and out of the modulating element by a tapering technique. Experimental results show that the light attenuation in the system can be greatly influenced by only 2.0×10(-2) μL of the magnetic fluid under different magnetic field strengths. The saturated modulation depth is 43% when the magnetic field strength is 489 Oe. The response time of the system is <120 ms. Significantly, this work presents information for the development of all-fiber modulators, including other integrated electro-optic devices, such as optical switch, optical fiber filter, and magnetic sensors utilizing the special structure of this hollow optical fiber with suspended core and superparamagnetic magnetic fluid.     

Creating very slow optical gap solitons with a grating-assisted coupler

We show that optical gap solitons can be produced with velocities down to 4% of the group velocity of light using a grating-assisted coupler, i.e., a fiber Bragg grating that is linearly coupled to a non-Bragg fiber over a finite domain. Forward- and backward-moving light pulses in the non-Bragg fiber(s) that reach the coupling region simultaneously couple into the Bragg fiber and form a moving soliton, which then propagates beyond the coupling region. Two of these solitons can collide to create an even slower or stopped soliton.     

In vivo endoscopic optical coherence tomography by use of a rotational microelectromechanical system probe

A novel endoscopic optical coherence tomography probe was designed and constructed with a 1.9-mm microelectromechanical system (MEMS) motor. The new MEMS endoscopic probe design eliminates the need to couple the rotational energy from the proximal to the distal end of the probe. Furthermore, the endoscopic probe's sheath and fiber have the advantages of having a much smaller diameter and being more flexible than traditional endoscopes since no reinforcement is needed to couple the rotational torque. At the distal end, a prism mounted on a micromotor deflects the light rays to create a transverse circular-scanning pathway. Because our MEMS scanner does not require the coupling of a rotational single-mode fiber, a high scanning speed is possible while eliminating unstable optical signals caused by nonuniform coupling.     

L波段高掺铒光纤超荧光光源

采用半导体激光二极管泵浦12cm长高掺铒光纤,在双程前向装置中,获得了10.8mW最大超荧光输出功率,斜率效率10.6%,在1553.1~1588.6nm接近36nm的范围内,功率抖动小于0.2dBm。作为比较,在相同实验条件下泵浦10cm长的高掺铒光纤,结果显示输出光谱带宽明显下降,C波段的放大自发辐射远大于L波段的,由此也证明了L波段的放大自发辐射是由C波段的放大自发辐射泵浦产生的。     

光纤光栅压力传感器的理论建模及实验研究

鉴于压力传感器为工业生产中压力监控的一种必不可少的设备,分析了光纤光栅中心波长与光纤光栅应变之间的关系,阐述了带有硬中心的圆形膜片受到均匀压之后,膜片中心的挠度与压力之间的数学关系。在此基础上设计了圆形膜片作为流体压力转化光纤光栅敏感物理量的元件,并结合辅助元件完成对光纤光栅传感器组装,建立了传感器输入输出之间的线性数学模型。通过实验验证传感器线性度和重复性,运用数学计算得出了光纤光栅压力传感器各项参数,灵敏度Km=-0.658 nm/MPa,初始波长0=1 578.441 nm,为后期传感器稳定性作好了铺垫。     

Multimode fiber devices with single-mode performance

A taper transition can couple light between a multimode fiber and several single-mode fibers. If the number of single-mode fibers matches the number of spatial modes in the multimode fiber, the transition can have low loss in both directions. This enables the high performance of single-mode fiber devices to be attained in multimode fibers. We report an experimental proof of concept by using photonic crystal fiber techniques to make the transitions, demonstrating a multimode fiber filter with the transmission spectrum of a single-mode fiber grating.     

Phase-matched excitation of whispering-gallery-mode resonances by a fiber taper

We show that high-Q whispering-gallery modes in fused-silica microspheres can be efficiently excited by an optical fiber taper. By adjusting the taper diameter to match the ropagation constant of the mode in the taper with that of the resonant mode of interest, one can couple more than 90% of the light into the sphere. This represents a significant improvement in excitation efficiency compared with other methods and is, we believe, the most efficient excitation of a high- Q microcavity resonance by a monomode optical fiber yet demonstrated.     

基于FPGA的千兆以太网光纤转换器的设计

根据实际高清晰度LED大屏幕显示器远距离的传输需求,为了解决千兆以太网5类非屏蔽双绞线最长100米传输距离的瓶颈问题,选用了传输距离较远的光纤取代原有的5类非屏蔽双绞线。出于成本考虑,不改变原有发送与接收系统结构,设计了一种千兆以太网光纤转换器,通过基于FPGA的光纤端和千兆以太网端数据格式的转换及控制模块的设计,实现了以太网双绞线和光纤两种介质间的相互转换。将该转换器应用于高清晰度LED显示屏的实时数字视频传输系统中,取得了良好的效果,实现了远达10千米的实时数字视频传输,满足了未来一段时期内用户的需求,达到了设计的预期目标。     

Optical characterization of quantum dots entrained in microstructured optical fibers

We present a study of the basic optical properties of colloidal CdSe/ZnS core/shell quantum dots entrained in a microstructured optical fiber. Quantum dots suspended in heptane were pulled into the holes surrounding the solid core of a microstructured optical fiber of the holey fiber class via capillary action and are found to remain in the fiber. In this experiment, a laser coupled into the fiber photoexcited quantum dots along the length of the fiber. Quantum dot emission was observed to couple into the fiber core and propagate along the fiber. To investigate the use of such a system in fiber-based light generation or amplification, a second laser overlapping the low-energy portion of the quantum dot emission was simultaneously coupled into the fiber. We observed apparent amplification of this light when photoexciting the quantum dots well above their bandedge.     

Tilted superstructure fiber grating used as a Fourier-transform spectrometer

We propose and demonstrate a new method for fabricating a compact all-fiber spectrometer by using a tilted superstructure fiber grating to couple light out of a fiber core and produce an interference pattern in the near field. The Fourier transform of the interference pattern serves as a direct measurement of the optical input spectrum, and the superstructure grating design offers several degrees of freedom that permit control over the resolution and bandwidth of the spectrometer. For single-wavelength operation, the proposed scheme offers the possibility of making wavelength measurements with picometer-level precision over a broad 80-nm wavelength range while simultaneously providing coarser precision over a 160-nm range.     

具有存储功能的衍射图像光刻系统的研制

研制了一种在衍射光变图像器件上进行信息存储的新型数字化激光光刻系统。采用空间光调制器作图形自动输入,双远心投影成像系统在光刻记录面上缩微图形。通过光栅干涉光学头对记录面上的微图形进行干涉调制,使微图形上产生干涉条纹,条纹空间频率范围为500-1200lp／mm。在光刻胶干版上的存储实验表明,在衍射光变图像上的单角度存储信息密度大于3．7Mbit／cm^2。改变干涉条纹取向、条纹间隔和需要存储的图形,光刻系统可实现信息的旋转复用存储。上述光刻系统将会在防伪和衍射光变图像器件制造领域有良好应用。     

The Influence of Defects on the Propagation Light within Polymeric Optical Waveguides Studied by Polarized Near-Field Scanning Optical Microscopy

We have developed a polarization-preserving near-field scanning optical microscopy (NSOM) optical fiber probe and with it observed the influence of defects and weak stresses on a propagation light within polymeric optical waveguides. To characterize the influence, we intentionally printed an indentation in the vicinity of the waveguide and then evaluated the resulting influence using polarized guide-collection-mode NSOM images taken around the indentation. When transverse magnetic polarized light enters a waveguide, the light intensity becomes greater on the near side of the indentation than on the far side, as measured by a linearly polarized component perpendicular to the direction of light propagation. The most probable cause of this phenomenon is microdefects generated by the printing of the indentation. The polarized NSOM technique is useful in searching for small defects or stresses within integrated photonic devices.