波导多层光卡读出系统的研制

研制了适合于波导多层光卡(WMOC)的数据读出系统.该系统硬件主要包括了光卡器件、寻址部分、光学部分和信号读取与处理部分等多个单元;软件采用Visual Basic(VB)语言编程,设计了简单直观的操作界面,通过界面可以精确改变电控平移台的位置,实现对光卡寻址和显微放大光学单元的实时调节.该系统使用方便、具有很强的可操作性与实际应用价值.     

Statics characteristics of two Bose-Einstein condensate dark solitons trapped in an optical lattice

The statics characteristics of two coupled Bose-Einstein condensate （BEC） dark solitons trapped in an optical lattice are investigated with the variational approach. It is found that the interaction between a ‘kink＇ and an ‘anti-kink＇ with opposite phase gradients is effectively repulsive, and the optical lattice can be controllably used to produce a pair of static BEC dark solitons. Its effect depends on the initial location of the BEC dark solitons, the lattice amplitude and wave number.     

High power output quasi-continuous-wave nanosecond optical parametric generator based on periodically poled lithium niobate

We report on a high power output quasi-continuous-wave nanosecond optical parametric generator （OPG） of congruent periodically poled lithium niobate （PPLN） pumped by a 1 064 nm acousto-optically Q-switched Nd-YVO4 laser （duration. 70 ns,repetition rate：45 kHz,spatial beam quality M2〈 1,3）. The OPG consists of a 38.7 mm long PPLN crystal with a domain period of 28.93 μm. With 5.43 W of average pump power the maximum average output power is 991 mW at 1 517.1 nm signal wave of the PPLN OPG.     

Influence of reaction temperature on the formation process of ZnO quantum dots and the optical properties

ZnO quantum dots (QDs)with the sizes of 3.0-5.6 nm are synthesized by solution-phase method at different temperatures. We find that temperature has great influence on the size of ZnO QDs. The growth process is the most sensitive to temperature, and the process is well explained by Lifshitz-Slyozov-Wagner (LSW) model. By photoluminescence (PL) spectra of the quantum dots at different temperatures and reactive time, we come to a conclusion that ultraviolet emission is mainly due to surface defects, and the or...     

Design and fabrication of sub-μs silicon-on-insulator thermo-optic 4×4 switch matrix

A rearrangeable nonblocking silicon-on-insulator-based thermo-optic 4x4 switch matrix with spot size converters （SSCs） and a new driving circuit are designed and fabricated. The introduction of a spot size converter （SSC） has decreased the insertion loss to less than 10dB and the new driving circuit has improved the response speed to less than l~s.     

80nm FBG sensing interrogation system based on tilted FBG

An 800 nm band fiber Bragg grating sensing interrogation system using tilted FBG as the core wavelength division component is presented. A charge coupled device （CCD） linear array is put on the focal plane of the lens to detect the light. TFBG is used to tap light out of the fiber core to fiber cladding. The sensing wavelength is 795 to 830 nm, with accuracy of 20 pm and scan speed 100Hz. Using FBG sensor, we achieve the temperature sensitivity of 1.8 ℃ and strain sensitivity of 18 με.     

A parallel algorithm for evaluating general linear recurrence equations

A block parallel partitioning method for evaluating general linearmth order recurrence equations is presented and applied to solve the eigenvalues of symmetric tridiagonal matrices. The algorithm is based on partitioning, in a way that ensures load balance during computation. This method is applicable to both shared memory and distributed memory MIMD systems. The algorithm achieves a speedup ofO(p) on a parallel computer withp-fold parallelism, which is linear and is greater than the existing results, and the data communication between processors is less than that required for other methods. For solving symmetric tridiagonal eigenvalue problems, our method is faster than the best previous results. The results were tested and evaluated on an MIMD machine, and were within 79% to 96% of the predicted performance for the second order linear recurrence problem.Supported by the Texas Advanced Technology Program under Grant No. 999903-165 and the National Science Foundation under Grant No. MIP8809328.     

二维条码在波导多层光卡中的应用

针对波导多层光卡(WMOC)的特点,结合Data Matrix二维编码的特性,由此采用二维编码作为WMOC信息存储的方式,并提出一种寻址方法来满足信息的随机读取。结果表明:以Data Matrix编码形式存储在光卡上的信息能够随机存取,并能被准确解译。     

A molding method to fabricate the waveguide multilayer card

Waveguide multilayer optical card （WMOC） is a new kind of three-dimensional storage device. A method of fabricating the WMOC using the molding technique is introduced in this paper. The fabrication of WMOC mainly includes data writing with hot embossing method and multilayer bonding with PDMS material. The structure of the WMOC is consisted with Polycarbonate （PC） as the core layer material and Polydimethylsiloxane （PDMS） as cladding layer. The experimental results demonstrate that the molding fabrication method is feasible and effective.     

Single-side-band optical modulation in SCM systems for high-speed optical transmission

In order to decrease dispersion penalty and increase the optical bandwidth efficiency,an optical single-side-band modulation(SSBM) scheme in sub-carrier multiplexing(SCM) is proposed.The principle of the SSBM is analytically presented,and a configuration for generating optical SSB signal is proposed using a balanced Mach-Zehnder electro-optic modulator.     

Design and analysis on a Gires-Tournois resonator based interleaver

A flat-top interleaver,in which a mirror on one arm of the Michelson interferomefer is replaced by a G-T resonator,is proposed.In the interleaver,the parameters including the channel spacing of 50 GHz,ripple less than 0.05 dB,-0.5 dB passband of 43 GHz(86% of the spacing),-30 dB stopband of 42 GHz(84% of the spacing),and a channel isolation higher than 40 dB,are achieved.     

波导多层光卡的模压制作法

提出了波导多层光卡的一种模压制作方法.该方法以聚碳酸脂(PC)作为芯层,聚二甲基硅氧烷(PDMS)作为包层.首先通过传统的光刻过程制作带有信息的金属母板,然后用金属母板在PC表面压印信息坑,再在PC薄膜表面均匀地旋涂PDMS使之形成复合片,最后将多个复合片叠合在一起形成波导多层光卡.通过光源侧向耦合实验观察, 获得的光卡样品的数据图像清晰,表明这是一种可行的多层光卡制作方法.     

Second harmonic generation of a new nonlinear optical material：urea L-malic acid

SinceFrankenfirstobservedthesecondharmonic generationphenomenoninthequartzcrystalin1961,nonlinearoptics(NLO)materialscapableoffrequency conversioneffect,electro opticeffect,andphotorefractiveeffectivehavebeenactivelysoughtoverthelastfour decadesduetotheco…     

Influence of the nonlinear phase and ASE noise on DPSK balanced optical receiver in optical fiber communication system

The analytical expression of bit error probability in a balanced differential phase-shift keying(DPSK) optical receiver considering nonlinear phase noise and EDFA ASE noise is given,which is very useful to estimate the performance of DPSK balanced and unbalanced receiver in optical communication system.Through analysis,if only nonlinear phase noise is considered,both the balance and unbalanced receivers have the same performances.But if adding the ASE noise of EDFA,the balanced receiver is better.     

基于数据采集卡和多路复用器的多轴电动光学调整台控制器

建立了基于数据采集卡和多路复用器的多轴电动光学调整台控制器,并应用在积分散射仪中。控制器利用数据采集卡的数字输出和计数器脉冲输出功能,分别发送地址信号到多路复用器和脉冲信号到步进电机驱动器,实现了对调整台的点位控制。基于LabView开发了独立的控制软件和可供调用的子程序。控制系统在硬件和软件上都完全集成到积分散射仪中。     

Cell arrival modeling and related statistical multiplexer performance in ATM networks

A source is assumed to go through independently distributed ON and OFF periods. During an ON period, cells arrive spaced apart in time by a fixed interval. No cells arrive during an OFF period. The probability distribution of the ON and OFF periods are arbitrary. Traffic from a number of such sources is statistically multiplexed. The related statistical multiplexer performance is studied analytically as follows. A statistical multiplexer is modeled as a discrete-time single-server queueing system where the traffic from a new source (conforming to the cell arrival process described above) joins traffic that is already being statistically multiplexed. The aggregated arrival of cells from existing traffic is assumed to follow a two-state Markov modulated cell arrival process. Numerical examples that relate the performance at the statistical multiplexer to the parameters describing the traffic from the new source and the aggregated traffic are presented.This research was supported in part by the National Science Foundation under Grant No. NCR-9016348, and by the Pacific Bell External Technology Program.     

Electromagnetically induced transparency induced by a 100% amplitude-modulated coupling field

We present a study of electromagnetically induced transparency(EIT) under the excitation of a 100% amplitude-modulated(AM) coupling field.The EIT feature is associated with a Λ type three-level configuration where a coupling and probe field couples two separate optical transitions and it is well-known that the spectrum of the swept probe field gives a simple single transparency feature induced by the single mode coupling field.It is shown that when a 100% AM coupling field is applied,there is an EIT doublet...     

Spectral properties of partially coherent chirped Airy pulsed beam in oceanic turbulence

Spectral shifts and spectral intensities of partially coherent chirped Airy pulsed(PCCAP) beams propagating through oceanic turbulence are studied, where spectral properties of partially coherent chirped Gaussian pulsed(PCCGP) beams are also compared. The effects of optical parameters and oceanic turbulence parameters on spectral shifts at different observation positions are mainly discussed. It is shown that the spectral shift of PCCAP beam is richer than that of PCCGP beam, and there exists some critical positions for PCCAP beams where the spectral red-shift reaches its maximum. The spectral red-shift increases with increasing chirped parameter, correlation length or decreasing pulse duration. However, the increasing of spectral red-shift is accompanied by increasing dissipation rate of turbulence kinetic energy in unit mass liquid or decreasing relative intensity of temperature and salinity fluctuations, mean square temperature dissipation rate. A physical explanation of rapid spectral transition is also made.     

Measurement of linewidth enhancement factor of SOA using fiber Sagnac Ring

Semiconductoropticalamplifiers(SOA)arewidely usedincommunicationsystembecauseoftheirsmall volumeandlowpowerconsumption.Theycanbeusedasboosters,on lineamplifiers,andpreamplifier.Asnon linearcomponents,theycanalsobeusedinoptical switch,multiplexers/demultip…     

Blind equalization and automatic modulation classification based on subspace for subcarrier MPSK optical communications

Equalization can compensate channel distortion caused by channel multipath effects, and effectively improve convergent of modulation constellation diagram in optical wireless system. In this paper, the subspace blind equalization algorithm is used to preprocess M-ary phase shift keying (MPSK) subcarrier modulation signal in receiver. Mountain clustering is adopted to get the clustering centers of MPSK modulation constellation diagram, and the modulation order is automatically identified through the k-nearest neighbor (KNN) classifier. The experiment has been done under four different weather conditions. Experimental results show that the convergent of constellation diagram is improved effectively after using the subspace blind equalization algorithm, which means that the accuracy of modulation recognition is increased. The correct recognition rate of 16PSK can be up to 85% in any kind of weather condition which is mentioned in paper. Meanwhile, the correct recognition rate is the highest in cloudy and the lowest in heavy rain condition. This work has been supported by the National Natural Science Foundation of China (No.61671375), and the Industrial Research of Science and Technology Plan of Shaanxi Province (No.2016GY-082). E-mail:chdh@xaut.edu.cn