Development of an Integrated Multiwavelength Optical Computing System

在这个项目中，我们研究了集成多波长光计算系统的潜力-一种采用光波长分量作为可复用信息载体的并行计算系统。我们还开发了一种“自适应波长选择器”，作为多波长光学计算的关键组件。自适应波长选择器由波长检测器阵列和自适应计算电路组成。我们制作了两种不同类型的波长检测器阵列，采用(1)四个不同的介质多层薄膜滤波器（集成在光电二极管阵列上），其通频带分别在635nm， 690nm， 750nm和830nm左右调整；(2)一个楔形介质多层薄膜滤波器沉积在光电二极管阵列上，能够同时分离630nm至850nm的多个波长成分。我们证实了(2)型阵列更适合集成多波长光学计算，因为它可以很容易地通过单级图像化制作，并且可以使用自适应计算电路区分8 - 16个波长成分。研究了集成多波长光学器件对高并行互连网络设计的影响。我们提出了一个多波长光学超立方体，并表明使用8 - 16个波长可以使网络区域复杂性降低1/64 - 1/256，与单波长实现相比。我们还提出了用于点对点和广播通信的自由空间多波长光互连架构，使用集值逻辑的多波长光计算系统以及无互连的光神经网络。此外，这些想法被推广到使用调制电信号构建线高效VLSI计算架构的“多路计算”范式。

In this project, we investigated the potential of an integrated multiwavelength optical computing system - a parallel computing system that employs optical wavelength components as multiplexable information carriers. We also developed an "adaptive wavelength selector" as a key component for multiwavelength optical computing.1. The adaptive wavelength selector consists of a wavelength detector array and an adaptive computing circuit. We fabricated two different types of wavelength detector arrays employing (1) four distinct dielectric multilayer thin-film filters (integrated on a photodiode array) whose pass-bands are adjusted around 635nm, 690nm, 750nm and 830nm, respectively, and (2) a single wedge-shaped dielectric multilayer thin-film filter which is deposited on a photodiode array and is capable of separating multiple wavelength components ranging from 630nm to 850nm simultaneously. We confirmed that the type (2) array is more suitable for integrated multiwavelength optical computing, since it can be fabricated easily by a single stage of patterning and can discriminate 8 - 16 wavelength components using adaptive computing circuitry.2. The impact of integrated multiwavelength optics on the design of highly parallel interconnection net-works was investigated. We proposed a multiwavelength optical hypercube and showed that the use of 8 - 16 wavelengths makes possible the reduction of network area complexity by the factor of 1/64 - 1/256 in comparison with a single wavelength implementation. We also proposed free-space multiwavelength optical interconnection architectures for point-to-point and broadcast communications, a multiwavelength optical computing system using set-valued logic, and an interconnection-free optical neural network. Also, these ideas are generalized to obtain a paradigm of "multiplex computing" using modulated electric signals for constructing wire-efficient VLSI computing architectures.