Nikkhah Vahid, Mencagli Mario Junior, Engheta Nader
Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA.
Department of Electrical and Computer Engineering, University of North Carolina, Charlotte, NC 28223, USA.
Nanophotonics. 2023 Jun 13;12(14):3019-3027. doi: 10.1515/nanoph-2023-0152. eCollection 2023 Jul.
In recent years, wave-based analog computing has been at the center of attention for providing ultra-fast and power-efficient signal processing enabled by wave propagation through artificially engineered structures. Building on these structures, various proposals have been put forward for performing computations with waves. Most of these proposals have been aimed at linear operations, such as vector-matrix multiplications. The weak and hardly controllable nonlinear response of electromagnetic materials imposes challenges in the design of wave-based structures for performing nonlinear operations. In the present work, first, by using the method of inverse design we propose a three-port device, which consists of a combination of linear and Kerr nonlinear materials, exhibiting the desired power-dependent transmission properties. Then, combining a proper arrangement of such devices with a collection of Mach-Zehnder interferometers (MZIs), we propose a reconfigurable nonlinear optical architecture capable of implementing a variety of nonlinear functions of the input signal. The proposed device may pave the way for wave-based reconfigurable nonlinear signal processing that can be combined with linear networks for full-fledged wave-based analog computing.
近年来，基于波的模拟计算一直是备受关注的焦点，它通过波在人工设计结构中的传播来实现超高速和高能效的信号处理。基于这些结构，人们提出了各种利用波进行计算的方案。这些方案大多旨在进行线性运算，如向量 - 矩阵乘法。电磁材料的弱且难以控制的非线性响应给设计用于执行非线性运算的基于波的结构带来了挑战。在本工作中，首先，通过使用逆向设计方法，我们提出了一种三端口器件，它由线性和克尔非线性材料组合而成，具有所需的功率依赖传输特性。然后，将这种器件的适当排列与一组马赫 - 曾德尔干涉仪（MZIs）相结合，我们提出了一种可重构的非线性光学架构，能够实现输入信号的各种非线性功能。所提出的器件可能为基于波的可重构非线性信号处理铺平道路，这种处理可以与线性网络相结合，用于全面的基于波的模拟计算。
