Ultra-High-Capacity Optical Communications and Networking: Surface-Tension-Driven Liquid Space Optical Switching (SLISOS) Systems

本提案是应NSF 01-65关于“超大容量光通信和网络”的征集而提交的。提出了一种基于表面张力驱动微流体的新型液体空间光开关(LISOS)方法。这项研究的最终目标是超大容量，例如1024x1024的光交叉连接交换系统。性能的一些特点包括快速的开关时间(~100秒)、低插入损耗(~0.2分贝)、低串扰(~40分贝)、低功耗(~10W/开关)、固有的锁存功能(即无连续功率)和可逆的开关动作。这项技术将以极低的成本实现下一代超高速光通信。随着光纤通信的信号业务量迅速增加，无光电转换的全光交换技术被认为是最终的目标。使用光-电-光信号转换的传统交换方案根本不能满足下一代网络通信的高信号速率(例如，GHz-THz范围)要求。使用微机械反射镜直接切换光信号，消除了信号转换过程，已成为传统方法的主要替代方法。然而，将微镜方法扩展到超大容量光交叉连接面临着损耗特性和制造成本(劳动力和时间)方面的基本限制。最近提出使用热泡驱动的折射率匹配液体来替代基于微镜的方法。然而，由于大的、连续的功率需求，驱动特性并不是所希望的。此外，液体的热稳定性要求制约了最佳工作液体的选择。在本研究中，表面张力作为微尺度流体运动的主要作用力，被认为是LISOS的一种驱动机制。微驱动机构采用新型的表面张力电气机械控制(电润湿和机械润湿)，具有极低的功耗、运行可靠、执行速度快等特点。拟成立的团队将微流体技术与光子学能力相结合，将设计、制造和测试一种表面张力驱动的LISOS系统(SLISOS)，以满足具有上述性能的新出现的光通信需求的高容量、高速度要求。

This proposal was submitted in response to the solicitation NSF 01-65 on "Ultra-High Capacity Optical Communications and Networking." This proposal deals with an innovative liquid space optical switching (LISOS) method based on surface-tension-driven microfluidics. The final goal of this research targets ultra high capacity, e.g., 1024x1024, optical cross connect switching systems. Some of the featured aspects of performance include fast switching time (~ 100s), low insertion loss (~ 0.2 dB), low crosstalk (~ 40dB), low power consumption (~ 10W per switch), inherent latching function (i.e., no continuous power), and reversible switching action. This technology will enable next generation ultra high-speed optical communication at a very low cost.As the signal traffic for optical fiber communication rapidly increases, all-optical switching technology without opto-electronic conversion is considered the ultimate goal. The conventional switching scheme using optical-electrical-optical signal conversion simply cannot follow the high signal rate (e.g., GHz - THz range) requirement for next generation network communication. The use of micromachined mirrors for the direct switching of light signals, which eliminates the signal conversion process, has been a major alternative to the conventional approach. However, the extension of the micromirror approach to ultra high capacity optical cross connect is facing the fundamental limits in loss characteristics and manufacturing costs (labor and time). The use of thermal-bubble-actuated index matching liquid has been recently proposed as an alternative to the micromirror-based approach. The actuation characteristic, however, is not desirable due to large, continuous power requirement. Furthermore, the thermal stability requirement of the liquid restricts the choices of optically optimum working liquids.In this research, surface tension - a dominant force in microscale fluid motion - is proposed as an actuation mechanism for LISOS. The novel electrical and mechanical control of surface tension (Electrowetting and Mechanical Wetting) are used as microactuation mechanisms with extremely low power consumption, reliable operation, and high speed actuation. The proposed team, combining microfluidics technology with the photonics capability, will design, fabricate, and test a surface-tension-driven LISOS system (SLISOS) suitable to the high volume, high speed requirement of the emerging optical communication requirements with the aforementioned performance.