论文标题:应用于光通信的非硅基底光开关与光衰减器的研究
Non-Silicon Based Optical Switch and Variable Optical Attenuator for Optical Communications
论文作者 曹钟慧
论文导师 吴兴坤,论文学位 博士,论文专业 光学工程
论文单位 浙江大学,点击次数 95,论文页数 132页File Size13849k
2005-03-01论文网 http://www.lw23.com/lunwen_603474187/ 光无源器件;光开关;可调光衰减器;微加工;微机电系统
Optical passive device; Optical switch; Variable optical attenuator; MEMS; Micro-machining
光波作为信息载体,在通信领域发挥着越来越重要的作用。为了突破通信系统信息传输中“电子瓶颈”的限制,需要大力发展全光通信网络,研发一系列全光网络中的关键器件。光开关和可调光衰减器是组建全光网络的两种关键器件。光开关主要用于光信号的交叉连接(OXC),并实现分插复用(OADM)等,可调光衰减器主要用于短距离通信系统的信号衰减,实现增益平坦,宽带光纤传输中的各信道均衡等。作者在阅读国内外相关文献的基础上,利用实验室现有条件,对基于非硅基微加工技术的光开关及可调光衰减器的设计、制作进行了分析探讨和深入研究。 本文内容主要包括四大部分。 第一部分是研究背景综述(第一章),总结了本文的研究工作和贡献,介绍了全光通信与光无源器件的背景情况,综述了光开关和光衰减器的研究现状,并与本文设计的器件进行优缺点对比。 第二部分是非硅基底微加工型光开关的研究(第二章至第三章),研制开发了一种全金属化非硅基底可扩展1×8微加工型光开关。此种光开关具有开关时间短(2ms),低插入损耗和回波损耗等特点,特别是其反射单元落地面积较小,仅为3～4mm直径,在金属非硅基底微加工而成,可扩展为4×4反射单元阵列用于高端口光开关。本文应用有限元方法进行了器件开关时间的理论分析,器件的结构优化设计,并给出样品的实测结果。与国内外同类器件相比较,驱动电压低(±5V),能耗低;具有多数MEMS光开关不具有的断电自锁功能。制造工艺简单,成本低;利用独特设计,在非硅基底上采用微细电火花加工(EDM)技术,摆脱硅微加工的生产工艺复杂性,提高成品率,实现光开关的低成本批量国产化,并已通过浙江省经贸委的成果鉴定,受到鉴定专家的好评。 为了满足光开关阵列的装配要求,开发了一种光纤准直器阵列专用光路对准装置,该装置具有一个沿准直器光轴方向转动,两个正交方向上绕其出射端点的摆动和三个相互正交的方向上的平移共六个分解的调节自由度,同时消除了准直器出射光轴与摆动调节转轴交点之间的距离偏心,可广泛应用于光通讯器件封装领域的光纤准直器阵列的对准调节。该装置己获国家专利。 第三部分是非硅基底微加工型可调光衰减器的研究(第四章至第六章),针对现有
Lightwave plays an increasingly important role in communication. In order to break through the limitation of "electronic bottle neck", the development of all-optic communication network and key optical devices are indispensable. Optical switch and variable optical attenuator (VOA) are two of key components. Optical switch can be used for Optical Cross Communication (OXC) and Optical Add or Drop Multiplexing (OADM) in the node of networks. Variable optical attenuator is an important component in optical networks, providing gain equalization in optical amplifiers, signal attenuation for detector saturation protection, as well as power management for varying numbers of active channels. This dissertation studies the non-silicon based micro-machining optical switch and variable optical attenuator.The content of the dissertation is separated into two parts. One is the research of non-silicon based micro-machining optical switch and the other is the research of non-silicon based micro-machining variable optical attenuator. We studied these two devices from theoretical design and experiments.In the first part, we reported a low-cost non-silicon based fiber optic switch featuring a novel design of reflection cell, which is capable of ±5 V pulse operation and self-latching. The switch prototypes were measured to have a switch time less than 2 ms, return loss of 50 dB and low insertion loss. Enabling technology is Electrical Discharge Machining. The dynamic process of switching was analyzed using an FEA software ANSYS for design optimization. A reasonable agreement was observed between the measurement and simulation results. The switch is scalable to 4x4 or above and allows the realization of high capacity cross-connects. This project has passed Economic & Trade Commission appraisal.In order to match the assembly needs of optical switch arrays, we developed an alignment apparatus for fiber collimator array. The apparatus has six freedom of motion, one rotating round the optical axis of the collimator, two orthogonal oscillation around the exit point, and three orthogonal translational motion. The deviation between the axis of collimator axis and the rotation axis of oscillation is also eliminated. It has been granted Chinese patent.In the second part, a novel micro-machining based digital variable optical attenuator is developed. The design of the VOA was optimized to achieve a linear response and digitalizedvariation of attenuation. The characteristics of the device were analyzed with a scalar wave theory based numerical simulation. The performance test of the device showed a low insertion loss(0.5dB), low wave dependent loss(0.2dB), high return loss(>50dB), and wide dynamic response(0~40dB). It has been granted Chinese patent.A non-silicon micro-machining based 512-step fast digital VOA was designed and characterized in the last part of Sec.2. The device locates nine attenuating micro-filters in the beam path, with 0.1dB, 0.2dB, 0.4dB, 0.8dB, 1.6dB, 3.2dB, 6.4dB, 12.8dB,25.6dB attenuation respectively, and controls the states of a specified filter or some specified filters through digital control circuit, according to binary encoding conception, to achieve precise stepwise attenuations(0.1 dB). It offers a fast response time(less-than 1.9ms), low insertion loss(0.37dB), small wave dependent loss(0.2dB), and wide dynamic response(0~50dB). It has been applied for Chinese patent.A novel non-silicon based variable optical attenuator was reported at last. The VOA is comprised of an EDM micro-machined structure, in which a micro mirror is driven electro-magnetically to adjust for desired attenuation continuously.
|
