OptiLookUp: An Optical ROM-Based Lookup Table Engine for Photonic Accelerators
OptiLookUp:一种基于光学ROM的查找表引擎用于光子加速器
Ankur Singh, Akhilesh Jaiswal
AI总结 本文提出了一种基于光学ROM的查找表引擎,利用集成的微环谐振器实现高速可重构的光子ROM架构,通过直接在光子设备的频谱响应中编码输入输出映射,实现确定性的查找表操作,并在硅光平台上进行设计和评估,展示了在12.5GHz数据速率下的可靠性能。
详情
只读存储器(ROM)提供确定性的预定义数据映射访问。将ROM概念扩展到光学领域能够实现高带宽、低延迟和并行内存访问,但实现紧凑且可重构的光学ROM仍然具有挑战性,因为存在损耗、波长控制和集成限制。本文提出了一种高速、可重构的光子ROM架构,该架构采用集成的微环谐振器(MRRs)实现。ROM直接在光子设备的频谱响应中编码预定义的输入输出映射,从而在读取时实现确定性的查找表操作,而无需动态计算。为了提高可扩展性和减少累积插入损耗,该架构采用紧凑的银行子阵列,通过光学解码机制进行选择性寻址。可重构性通过基于晶体管的光学选择器实现,允许不同ROM银行被激活而无需物理光路重路由或干涉结构。所提出的光子ROM基于GlobalFoundries 45SPCLO硅光平台进行设计和评估。仿真结果表明,在12.5GHz的数据速率下能够可靠运行,通过集成的光电二极管读取获得了稳定的光到电流转移特性。该光学ROM可用于实现用于光子加速器架构中的非线性激活函数,包括Sigmoid、Tanh、ReLU和指数映射。
Read-only memory (ROM) provides deterministic access to predefined data mappings. Extending ROM concepts to the optical domain enables high-bandwidth, low-latency, and parallel memory access, but realizing compact and reconfigurable optical ROM remains challenging due to loss, wavelength control, and integration constraints. This work presents a high-speed, reconfigurable photonic ROM architecture implemented using integrated microring resonators (MRRs). The ROM encodes predefined input-output mappings directly in the spectral response of the photonic devices, enabling deterministic lookup-based operation without dynamic computation during readout. To improve scalability and reduce cumulative insertion loss, the architecture employs compact banked sub-arrays that are selectively addressed through an optical decoding mechanism. Reconfigurability is achieved using transistor-based optical selectors, allowing different ROM banks to be activated without physical light rerouting or interferometric structures. The proposed photonic ROM is designed and evaluated using device-level simulations based on the GlobalFoundries 45SPCLO silicon photonics platform. Simulation results demonstrate reliable operation at data rates up to 12.5 GHz, with stable light-to-current transfer characteristics obtained through integrated photodiode readout. The optical ROM can be used to implement nonlinear activation functions utilised in photonic accelerator architectures, including sigmoid, tanh, ReLU, and exponential mappings.