光弹调制器研究综述及原理验证

光弹调制器是一种基于压电效应和光弹效应的光学调制器件.光弹调制器采用共振工作模式,具有调制频率高,灵敏度高,调制波段宽(紫外～远红外)等特点,可广泛应用于半导体、新材料、生命科学及航天军工等高新技术领域.该文首先阐述了光弹调制器的基本工作原理,包括压电效应、光弹效应等;其次介绍了光弹调制器的结构和重要参数,并分析了不同...     

微纳光纤耦合器光致热引起的全光强度调控特性

对微纳光纤耦合器(OMC)光吸收致热引起的全光强度调控特性进行了理论分析和实验研究。理论分析结果显示,OMC全光强度调控器件的调制响应效率与OMC腰区长度、抽运光在OMC腰区的损耗系数及抽运调制光强成正比,而与OMC腰区耦合光纤的半径成反比。通过实验将强度调制的980nm抽运光注入OMC以加热其腰区,实现了对OMC传输的1550nm工作光的全光调控功能。在百微瓦量级的调控光功率作用下,OMC全光强度调控器件即可实现整周期、大调制深度的强度调制,且在较小调制光功率下,调制响应信号幅度与调制信号幅度呈线性响应关系。OMC光热调控最小响应调制光功率为几十微瓦量级。研究成果为开发基于OMC光致热效应的光衰减、光开关及强度调制器等全光功能器件提供了实验数据,并为微纳光子集成光路热稳定性管控及片基量子通信系统安全性研究提供了可借鉴的研究方案。     

多量子阱光开关器件的激子吸收及光调制特性

我们分析了 Ga As/Al Ga As半导体多量子阱 (MQW)光开关器件的室温激子吸收行为及光调制特性 ,优化设计了多量子阱结构 ,研制出常通型和常关型两种类型光开关器件 ,并对器件的光调制特性进行了测量与研究。实验得出的结论与理论计算相符合 ,常通型器件对比度约为 10∶ 1;常关型器件对比度约为 4∶ 1。     

集成光收发芯片中激光器调制特性研究

文章从理论上研究了一种应用于光纤到户(FTTH)网络中的基于单片集成的双端口光收发芯片,结合器件的结构和参数分析了该产品的直接调制特性,计算了其驰豫振荡、增益抑制和频率啁啾,得到了该器件的直接调制频率限制和频率啁啾效应下的输出光场表达式,并通过仿真分析得出了高频直接调制频率啁啾下的输出光频谱.     

空间光调制器件

1.前言 空间光调制器件(SLM)是一种用光和电信号实时空间控制另一光的振幅、相位或者进行方向等的器件,液晶显示器也是其中的一种,如果SLM也包括投射式显示器,那么SLM已有40多年的历史。最初SLM作为大画面显示器的时序信号处理器件发展起     

光纤相位转换通信技术

由于光在作相位调制时,其强度并不随时间改变,因此在光纤中传送相位调制的光信号并不会产生自我相位调制(SelfPhaseModulation,SPM)的非线形效应。另外作相位调制的光可抑制在传输过程中的激发布里昂散射(StimulatedBrillouinScattering,SBS)非线形效应。提出一种利用光的相位调制(PhaseModulation)信号透过特殊的色散器件达到转换为光的强度调制信号进行通信的构想,并探讨以这个转换过程作为基础的传输架构之可行性。     

高速DWDM通信技术及进展

综述了高速DWDM(密集波分复用)系统中的关键技术,包括QPSK(四相相移键控)、8QAM(8进制正交幅度调制)和16QAM(16进制正交幅度调制)等新型调制格式、超低损耗光纤/拉曼放大和新型光集成器件,并分析、比较了这些关键技术对DWDM系统传输产生的不同影响。在此基础上,介绍了近年来DWDM大容量传输的一些成功试验。试验表明,这些关键技术有着广阔的应用前景。     

基于体硅工艺的GLV光学调制器的研制

采用体硅微加工工艺制作了一种基于光栅光阀(GLV)的光学调制器,使用仿真软件对器件参数进行了优化设计。对加工出来的器件进行了测试,并对测试结果进行了分析。器件成功的实现了光学调制的功能,采用10kHz的方波信号进行调制时,得到了峰峰值为50mv,响应时间为10μs的调制后波形。     

声光器件的特性及应用

随着光电子学的发展,光学电子器件正在迅速地向实用化渗透,其中用电来控制光信号的手段之一,是称作布喇格元件,或AO元件的声光器件.为了发生光信号,除了直接开关光源的直接调制外,还有利用光源外部器件而进行的外部调制,通常,LED和半导体激光等是利用前者,而He-Ne激光等是利用后者.在外调制方面,除了以机械手段遮断光的方法之外,还有利用声光效应的声光器件,利用泡克尔斯效应和克尔效应等电光效应的电光器件和利用法拉第效应的磁光器件等.其中声光器件由于下述原因,     

导波结构的声光互作用与声光器件(一)

在各种固体介质中,光波与声波的相互作用,随着激光的问世与高频超声技术的发展,十几年来已为人们广泛地研究.许多实用的体波结构的声光器件(声光调制和声光偏转器等)也已研制成功.由于集成光学的发展,从1970年Kuhn等人第一次报导了导波结构的声光衍射实验以来,关于导波结构的声光互作用和声光器件的研究越来越多.这种新型的声光器件,由于光导波的导波特性使其与体波结构的器件相比,具有功率密度大、声光互作用的长度较长以及导波的色散可以控制等优点,在制作工艺上,这种器件采用薄膜平面工艺,可以制成小型化,并有利于成批生产.因而,导波结构的声光器件,在集成光学中可以作为一种有效的控制光束(光调制、光开关和光偏转)的元件.     

Laser diode arrays with apertured phase conjugate feedback

A study is made of the use of phase conjugate mirrors (PCMs) and filters which may destroy the phase conjugation quality, evoke coupling of the laser array modes (supermodes), and give new filter-dependent cavity modes. An analysis is made of this coupling and the degree of feedback as a function of the spatial filtering. In general, an increase of the spatial filtering deteriorates the phase conjugation quality, increases the coupling, and decreases the light intensity of the feedback. The applications for mode selection capabilities are given. In particular, the authors give a detailed example for a simple filter (a slit) which favors the basic (first) mode, although the highest mode is the preferred lasing mode without the filter. This is a very common situation in most of the commercially available laser diode arrays. The authors' analysis is based on the Fresnel diffraction regime, which can be applied in a cascaded form, and allows a separate calculation for each link of the light propagation     

感知泛在物联网

回顾了物联网近十年来的发展历程,介绍了国内外物联网的现状,并针对现今国内外发展形势,对今后物联产业的突破口进行了简单分析。最后对泛在物联网的发展前景进行了技术展望。     

基于PLC的十字路口交通灯控制系统

文中采用PLC可编程控制器控制十字路口信号灯,PLC可编程制器具有可靠性高、维护方便,用法简单、通用性强等特点.根据城市交通的实际情况,给出西门子S7-200型PLC实现带人行横道过马路请求的十字路交通灯控制系统的硬件和软件设计,给出了一种简单实用的城市交通灯控制系统设计方案.文中交通灯控制系统主要用于控制快速路十字路...     

Mesa-size dependence characteristics of vertical surface-emitting lasers

The vertical-cavity surface-emitting laser (VCSEL) is the most suitable light source for many optoelectronic applications because of its planar nature. The design of large VCSEL arrays requires accurate modeling of device characteristics. In this paper, we present a thermal model to analyze the dependence of VCSEL threshold current and light-output characteristics on aperture size. For both 850-nm and 980-nm VCSELs, a linear dependence of threshold current on device area is observed for oxidized aperture sizes with diameters between 5 μm and 25 μm. Good agreement between theoretical and experimental light-output characteristics is observed using a simple thermal model.     

Nanoimprinted Grating‐Embedded Perovskite Solar Cells with Improved Light Management

Organic–inorganic halide perovskite solar cells are one of the most efficient photovoltaic devices, and their power conversion efficiency (PCE) continues to grow rapidly due to the optimization of device architecture and functional materials. The involved optical design has an important impact on performance by affecting the light harvesting capability. Here, demonstrated is a simple and effective strategy to boost device performance from the perspective of light management. A diffraction grating pattern into the TiO₂ scaffold and antireflection layer is simultaneously introduced to construct a double grating design for perovskite solar cells. The grating pattern obtained using a commercial compact disk as the hard mold can modulate light transport by enhancing the light transmittance and, thus, light absorption in perovskite solar cells. The grating pattern‐induced light trapping can significantly increase the short‐circuit current density and PCE by 4.8% and 7.9%, respectively, on average. The present work develops a feasible method by tailoring the morphology‐related optical property to further improve the performance of perovskite solar cells. The double grating design can also generate structural color and can provide an alternative solution for fabricating colorful solar cells.     

计算机软件工程中的数据库编程技术研究

目前计算机已经形成一定的规模,但每个行业对计算机技术有着不同的性能要求,需要研发出符合实际情况的软件系统。文章针对计算机软件工程的数据库编程技术进行研究,在简单了解数据库编程技术运用现状后,从数据库建立、文件建立、数据库文件访问等方面入手,进行具体的技术分析,以供参考。     

Plastic Optical Fibers: An Introduction to Their Technological Processes and Applications

The most significant features of plastic optical fibers (POFs) are reviewed, including the main types of POFs, their manufacture, and their possible present and future applications. Among others, their properties regarding bandwidth, attenuation, and influence of external parameters are discussed. These fibers serve as a complement for glass fibers in short-haul communications links, because they are easy to handle, flexible, and economical. Because of these merits, varied applications with POFs have been developed and commercialized, from their use as a simple light transmission guide to their utilization as sensors and telecommunications cables. This paper is a comprehensive introduction to POFs. In addition, its great number of references facilitates further inquires about the subject.     

基于BH1750FVI的绝缘子灰密测量系统设计

灰密(非可溶沉积物密度,NSDD)是指附着在绝缘子表面不能溶解于水的物质除以表面积得到的结果,用于定量标示绝缘子表面非可溶残渣的含量.通过对高压设备外绝缘的表面进行灰密测量,可以了解线路绝缘子的积污情况,确定它是否能承受各种不利因素的影响.本文提出了一种基于BH1750FVI光强传感器测量灰密的方法.     

垂直腔表面发射激光器的研究

垂直腔表面发射激光器(VCSEL)是一种应用于光纤通信系统的低成本、高性能的特定波长光源,它具有测试简单、易耦舍以及易形成阵列等独特优势,已在光并行互连及高密度光存贮等领域得到大规模应用.文章介绍了VCSEL的结构和当前的制造工艺水平,阐述了各波段VCSEL的发展和应用现状,探讨了VCSEL在不同领域中的应用范围并指出了VCSEL的发展前景.     

Gain Control of Semiconductor Optical Amplifier Using a Bandpass Filter in a Feedback Loop

The authors present a simple configuration of a gain-clamped semiconductor optical amplifier (GC-SOA) based on automatic intensity control of a feedback light generated by amplified spontaneous emission, using a narrow bandwidth thin-film-tunable filter. Experimental results show that the proposed amplifier has good gain clamping characteristics and the feedback light dramatically reduces steady and transient gain variations. The feedback light operates satisfactorily with the channel's add-drop frequency up to 20.9 kHz. We also examined the performance of the GC-SOA by employing the feedback light at different wavelengths.