Ultra High Capacity WDM Device Based on Novel Phased Array Design and Laser Fabrication of 3-D Optical Waveguides

由于密集波分复用(DWDM)系统提供了非常大的传输容量和新的网络体系结构，因此对密集波分复用(DWDM)系统的技术兴趣正在快速增长。密集波分复用系统中的主要部件是波长复用器和解复用器，如阵列波导光栅(AWG)。然而，当前AWG器件的容量在可在给定体积中制造的通道数量方面是有限的，因为它们使用光刻技术以及涉及规则采样和有限使用相位调制的算法的2-D几何结构。这项工作将通过将新的AWG设计方法和基于激光的新制造技术相结合来设计和制造新一代三维AWG。密集波分复用中使用的相控阵设备的一个主要瓶颈是允许的自由频谱范围(FSR)。我们将开发一种新型的密集波分复用(DWDM)系统，其中每个波长只有一个有效阶，从而不会因为FSR而限制对应于不同波长的通道或图像的数量。该方法涉及对线性和/或球面参考波的相位过零点进行不规则采样。这种方法还允许设计具有AWG通道数量的非常大的增加的3-D系统。在采用飞秒激光制造技术的三维密集波分复用系统的设计中，我们将实现规则和非规则采样的AWG。通过将飞秒激光聚焦在介质中以增加激光焦点处的折射率，并借助三维计算机辅助设计和制造，可以制造出真正的三维波导，它是三维AWG器件中的关键部件。为了针对各种误差源进行优化，并结合多功能系统行为，我们还将结合用迭代最小均方误差方法优化的衍射光学元件和闭环制造技术。该工作的成功将在多光谱通信、联网和计算方面具有很大的发展潜力。在复杂的微纳系统中，超大容量波分复用(WDM)等技术将在部件通信方面发挥更大的作用，对波长的需求也会越来越大。3D技术的进步将开启全新的可能性，带来巨大的容量增长和全新的设计技术。该项目由化学和运输系统部门的热运输和热加工项目以及设计、制造和工业创新部门的材料加工和制造项目联合发起。

This proposal was submitted and funded in response to solicitation NSF 03-537 High Speed Optical Communications and Networks.Technological interest in dense wavelength division multiplexing (DWDM) systems is fast increasing since DWDM systems offer a very large transmission capacity and new novel network architectures. Major components in DWDM systems are the wavelength multiplexers and demultiplexers, such as arrayed waveguide grating (AWG). However, the capacity of current AWG devices is limited in terms of the number of channels that can be manufactured in a given volume because of their 2-D geometry using lithography techniques as well as algorithms used involving regular sampling and limited use of phase modulation. The proposed work will design and manufacture a new generation, 3-D AWGs by combining novel design methodologies of AWGs and novel laser-based manufacturing techniques. A major bottleneck in phased-array types of devices used in DWDM is the free spectral range (FSR) allowed. We will develop a novel dense wavelength division multiplexing (DWDM) system in which there is only one effective order per wavelength so that the number of channels or images corresponding to different wavelengths is not restricted due to FSR. The method involves irregular sampling of zero-crossings of phase with linear and/or spherical reference waves. This method also allows the design of 3-D systems with a very large increase in the number of AWG channels. We will implement regularly and irregularly sampled AWGs in the design of 3-D DWDM systems using the femtosecond laser manufacturing technology. By focusing a femtosecond laser beam inside a dielectric media to increase the index of refraction at the laser focal point, and with the aid of 3-D computer aided design and manufacturing, truly 3-D waveguides, which are essential parts in the 3-D AWG devices can be fabricated. In order to optimize against various error sources and to incorporate multifunctional system behavior, we will also incorporate diffractive optical elements optimized with iterative minimum mean-squared error methods and a closed loop manufacturing technique.The success of the proposed work will have very high potential for progress in multispectral communications, networking and computing. Topics such as ultra high capacity WDM will be more significant in the upcoming progress for communications of parts in complex micro/nano systems, and the demand for more and more number of wavelengths will increase. Progress in 3D will open up completely new possibilities and bring along tremendous increase in capacity, and totally new design techniques. The project is being jointly sponsored by the Thermal Transport and Thermal Processing Program of the Chemical and Transport Systems Division and the Materials Processing and Manufacturing Program of the Design, Manufacturing and Industrial Innovation Division.