Wideband tunable Gaussian-shaped spectral filters based on dispersion engineering

Optical liquids can be used to engineer the dispersion characteristics of fibers by serving as the core or cladding to attain fundamental-mode cutoff effect. The short-/long-pass fiber filters are so made and concatenated to achieve widely thermo-optic tunable Gaussian-shaped spectral filters. The proposed wideband tunable Gaussian-shaped spectral filter provides a potential technique in application to high resolution bio-imaging.     

Non-blocking wavelength channel switch using TO effect of doubles series coupled microring resonator

A non-blocking wavelength channel switch (non-blocking tunable filter) using the thermo-optic (TO) effect of a double series coupled polymer microring resonator is demonstrated. This device can switch a wavelength channel without blocking other wavelength channels. An extinction ratio of more than 10 dB was realised.     

Low switching power silica-based super high delta thermo-opticswitch with heat insulating grooves

A silica-based 2×2 thermo-optic switch with super high delta planar lightwave circuits has been fabricated and used with a low switching power configuration. This switch has two features that aid switching power reduction, namely heat insulating grooves and a thick undercladding. Dependence of the switching characteristics on these features has been examined both theoretically and experimentally. A very low switching power of 45 mW has been achieved     

Thermo-optic effect in LiNbO3, for light deflection and switching

Light deflection and switching in LiNbO3 via thermo-optic effect based on the temperature dependence of the refractive index are demonstrated. The switching speed of 1 ms order has been confirmed in the thermo-optically induced waveguide switch.     

Ultra-low power thermo-optic silica-on-silicon waveguide membrane switch

An optimised ultra-low power thermo-optic waveguide switch design is presented. Under 25 mW power consumption was achieved for standard index-contrast silica-on-silicon material with reduced polarisation-dependent switching performance     

SOI热光4×4光开关阵列的研制

设计和制作了由5个2×2多模干涉马赫-曾德开关元组成的重排无阻塞型SOI 4×4热光开关阵列.阵列的最小和最大附加损耗分别为6.6和10.4dB,阵列的串扰为-12 ～-19.8dB,光开关阵列的开关速度小于30μs,单个开关元的功耗大约为330mW.     

A coherent photonic wavelength-division switching system forbroad-band networks

A coherent photonic wavelength-division (WD) switching system, utilizing a coherent wavelength switch (λ switch), is proposed. In the proposed coherent λ switch, the tunable wavelength filter function is accomplished using coherent optical detection with a wavelength tunable local oscillator. The coherent photonic WD switching system has the following features; (1) low crosstalk switching for dense WDM signal, and (2) large line capacity capability. Design considerations show that 32 wavelength division channels can be available with a coherent λ switch. It is also shown that a broadband metropolitan-area-network with over 1000 line capacity is possible, using a multistage connection in the coherent λ switches. The switching function of the coherent λ switch is demonstrated in a two-channel wavelength-synchronized switching experiment, using 8-GHz-spaced, 280-Mb/s optical FSK signals     

Solid state optical space switches for network cross-connect andprotection applications

Network protection and reconfiguration is becoming increasingly important in fiber optic communications systems. This is driven by the intense traffic and high cost of lost high-data-rate optical connections. Optical cross-connects at the nodes in transmission systems are developing rapidly in response. A key optical component required for these applications is an optical space switch. Since the required timescale of network reconfiguration at the optical level is on the order of 50 ms to prevent electrical intervention. The optical space switching speed must be approximately 5 ms or faster. The demand created by these applications has motivated the development of a solid state optical space switch based on a novel planar-waveguide technology. This planar integrated optics technology relies on the thermo-optic effect in specialized optical polymer materials and results in reliable optical space switches without moving parts to wear out. This article reviews the state of the art in solid state optical space switches based on thermo-optic polymers and applications of these switches in network communication systems. The same polymer-based planar waveguide technology used to make the solid state optical space switches of today provides the basis for WDM devices. Electro-optic modulators, and devices integrating several functions (space switching, wavelength multiplexing, light generation and detection) in one component in the years to come     

Optical channel switching algorithm for continuously tunable lasers

A novel idea and realisation of a control algorithm to switch the wavelength of continuously tunable lasers is presented. The concept allows the switching of a defined number of dense wavelength division multiplexed (DWDM) channels up or down by employing a broadband wavelength locker. The switching algorithm is implemented and demonstrated for a micro-electro-mechanically tunable vertical-cavity surface emitting laser (MEM-VCSEL).     

全光通信中的光开关技术

光开关是实现全光交换的核心器件,光开关的研究已成为全光通信领域研究的焦点。本文首先对光开关的原理进行归纳,总结光开关的应用范围。对传统机械式光开关、微电子机械式光开关、热光开关进行了进一步地划分,分析了它们的结构形式和性能特点。设计了光开关性能评价指标体系,对常见的4种光开关进行了定性与定量对比,指出不同类型光开关的优点和不足之处。最后依据全光通信网的发展趋势,指出大容量、高速、透明、低损耗是光开关的重点发展方向。     

基于Fabry-Perot结构的可调波长选择光开关

本文提出波长选择光开关的概念,首次研制出一个基于Fabry-Perot结构的可调波长选择光开关,该开关为2×2光纤端口,每个端口携带N个波长,工作时可以选1个或多个波长,插入损耗小于3dB,波长调谐范围10nm,调谐机构为一对多层三明治结构的压电陶瓷,具有驱动电压低,小于5V的驱动电压可以达到3.3nm的调谐,最大开关时间为1毫秒,开关比优于30dB.最后还分析了其基本透射与反射光谱性能,并讨论其对光通信、光交换网络产生的重要应用价值.     

Delayed self-multiplex light source for frequency-agiletransmitters

The delayed self-multiplex (DSM) light sources proposed in this paper provide multiple frequency-agile outputs from a single tunable laser. The DSM light source employs multiple fiber delay lines and optical switches, and overcomes the intrinsic tuning-speed limitation and thermal frequency drift of the tunable laser. Practical switching performance restricted by the optical switch is analyzed and examined in a delayed self-duplex (DSD) light source constructed with a tunable DBR laser and a LiNbO₃ electrooptic switch. Bit-error-free operation of the frequency-agile transmitter is achieved in 622 Mb/s transmission; the power penalty due to the DSD light source is 1.8 dB     

低功耗有机/无机混合结构热光开关的研制

利用聚合物材料SU-8作为芯层、聚合物材料PMMA作为上包层和无机材料SiO2作为下包层,设计并研制了一种有机/无机混合结构的Mach-Zehnder干涉(MZI)热光(TO)开关。为了保证波导中的单模传输、减小模式辐射损耗和衬底泄露损耗、缩短响应时间并降低器件功耗,对其结构参数做了优化。利用化学气相沉积(CVD)、涂膜和湿法刻蚀等工艺制备了器件样品。在1 550nm工作波长下,器件的开和关状态的驱动功率分别为0和13mW(开关功率为13mW),开和关状态间的消光比为18.3dB。在方波驱动电压信号作用下,测得器件的上升和下降时间分别为126和134μs。与无机材料Si/SiO2和全聚合物材料研制的TO开关相比,本文研制的混合结构器件综合利用了芯层聚合物材料热光系数大、上/下缓冲层厚度均较小以及Si/SiO2导热系数大的优点,因此同时具备了较低的功耗和较快的响应时间,在光通信系统中具有较好的应用前景。     

Fast and stable frequency switching employing a delayed self-duplex(DSD) light source

A novel frequency-agile light source, the delayed self-duplex (DSD) light source, is constructed using a tunable DBR laser and an optical switch. The DSD light source overcomes the tuning speed limitation of the tunable laser, and also offers suppressed frequency drift due to the thermal effect by employing periodic laser tuning. For 160-GHz-spaced frequency switching, the 4-ns switching time and 2.2-GHz thermal frequency drift inherent to the DBR laser are reduced to 0.4 ns and 0.3 GHz, respectively     

聚合物热光光开关器件驱动与控制单元的研制

在分析了聚合物热光光开关工作特点以及集成光开关器件的工作状态矩阵的基础上,设计了一种新的简洁可靠的聚合物热光光开关器件驱动与控制单元,有效的提高了光开关器件的工作效率。     

有机聚合物热光开关的研究进展

对热光开关的研究现状进行了综述，并提出一种推挽式全内反向型新结构。     

Widely tunable filter based on side-polished polarisation-maintaining fibre coupled with thermo-optic polymer overlay

A wide wavelength tunable filter based on a side-polished polarisation-maintaining fibre in contact with a polymer planar waveguide overlay is proposed and demonstrated. The good thermo-optic effect of the polymer waveguide induced by a micro-strip heater leads to a wide tunable wavelength range of 230 nm with an applied electrical power of 0.76 W.     

定向耦合器热光光开关的设计和特性模拟

对定向耦合器热光光开关的工作原理做了介绍。描述了这种热光光开关的一般设计方法，并且用ＢＰＭ方法（光束传输法）分析了它们的传输特性，提出了几种改善这一光开关波长不敏感特性的方法。     

用低压KTP普克尔盒和微带传输线进行调Q长脉冲的任意整形

利用新电光材料ＫＴＰ晶体的有效电光系数γｃ１,制成电光开关,实验研究了它的热光效应。成功地用它对输出脉宽为５０ｎｓ的ＮｄＹＬＦ单纵模调Ｑ激光削波整形。实验表明,ＫＴＰ普克尔盒的半波电压低及电容小,配合微带传输线后,能够获得脉宽为１～１０ｎｓ,形状几乎任意可调的整形脉冲,改变了过去那种只把普克尔盒当作简单的削波元件、而无整形能力的状况。并提出了采用双块晶体、补偿结构ＫＴＰ普克尔盒的设想     

Semiconductor devices in photonic switching

Three types of photonic switching networks have been proposed, namely, optical space-division switching, optical wavelength-division switching. Optional function devices required for each switching network are as follows: optical switch matrix for space-division switching; optical memory and optical write/read gate for time-division switching; and tunable wavelength filter and wavelength converter for wavelength-division switching. Recent progress in semiconductor functional devices such as modulators, switching devices, bistable devices, and wavelength control devices, which would be key devices to build switching networks, is reviewed