Hybrid analytical/computational methods for the identification of errors in lightwave systems

用于传输和处理信息的高速光学系统的发展是二十世纪末的一项重大技术成就。该项目的目标是开发新的混合分析/计算技术，能够确定限制这类系统性能的错误及其发生的概率。该项目的第一个组成部分是将奇异值分解应用于控制光脉冲传播和传输结束时将光转换为电能的信号检测的组合的方程，这将确定在输出端产生最大变化的扰动。第二个部分是交叉熵方法的应用，这是一种自适应方差减少技术，根据概率评估每种扰动的相对重要性。光学系统的实验测试和实验室或现场测量可能相当昂贵，需要数月时间。该项目的一个目标是开发能够以有效方式提供有关系统性能的详细信息的模拟方法，从而减少对测试的需要。这些方法将被用于对高速光通信系统和新型极稳定的短脉冲激光器进行建模。这些激光器为通信、雷达和远程化学传感提供超精密的频率基准，是光学原子钟的重要组件，光学原子钟是下一代计时设备，预计其精度将比目前的原子钟高出几个数量级。这些设备有望提高全球定位系统和其他技术的精度。

The development of high-speed optical systems to transmit and process information is a major technological achievement of the late twentieth century. The goal of this project is to develop new hybrid analytical/computational techniques capable of identifying the errors that limit the performance of such systems, and the probabilities with which they occur. The first component of the project is the application of the singular value decomposition to the equations governing the combination of optical pulse propagation and signal detection at the end of transmission that converts light into electrical energy, which will determine the perturbations that produce the largest changes at the output. The second component is the application of the cross-entropy method, an adaptive variance reduction technique which assesses the relative importance, in terms of probability, of each type of perturbation.Experimental testing and laboratory or field measurements of optical systems can be quite costly and require months of time. A goal of this project is to produce simulation methods that can provide, in an efficent manner, detailed information about system performance, thus reducing the need for testing. The methods will be used to model both high-speed optical communication systems and new classes of extremely stable short-pulse lasers. These lasers provide ultra-precise frequency references for communication, radar, and remote chemical sensing, and are an essential component in optical atomic clocks, next generation timekeeping devices that are predicted to have accuracies several orders of magnitude better than current atomic clocks. Improved accuracies in global position systems and other technologies are expected to result from these devices.