Abstract

During the past years, the limited access-times and memory bandwidth in electronic random-access memory (RAM) has triggered a concerted research effort towards deploying optical memory circuitry for exploiting the inherent high-bandwidth characteristics of light-based technologies. Yet the deployment of optical memory elements in functional optical RAM demonstrations has still been limited to single-bit capacity levels, with the few multi-bit demonstrations still offering only storage functionality without any true random-access capabilities. In this article, we demonstrate an experimental 16-bit all-optical RAM bank prototype that follows a 4 × 4 matrix organization and supports addressable random access storage of four 4-bit WDM-formatted optical Data Words at a 20 Gb/s memory-throughput. The proposed architecture constitutes of completely passive Row/Column decoding (RD/CD) subsystems, four Semiconductor Optical Amplifier Mach-Zehnder Interferometer (SOA-MZI) Access Gates (AGs) for enabling the access towards the 4 available Word Lines (WLs) and 16 all-optical Flip-Flops (AOFF) arranged in a 4 × 4 RAM bank. Each FF is incorporated in an indicative photonic integrated circuit (PIC). The experimental validation of the complete 16-bit RAM bank reveals error-free operation in Write mode with a peak power penalty between 8.3–10.2 dB at 10⁻⁹ bit-error-rate (BER) measurements, indicating a roadmap for two-dimensional addressable (2D) RAM banks that can penetrate the optical computing application domain.

10  Gb/s optical random access memory (RAM) cell

Apostolos Tsakyridis, Theoni Alexoudi, Amalia Miliou, Nikos Pleros, and Christos Vagionas
Opt. Lett. 44(7) 1821-1824 (2019)

Design for an optical random access memory

Miles J. Murdocca and Binay Sugla
Appl. Opt. 28(1) 182-188 (1989)

Polycube optical memory: a 6.5 × 10⁷ bit read–write and random access optical store

B. Hill, J.-P. Krumme, G. Much, R. Pepperl, J. Schmidt, K. P. Schmidt, K. Witter, and H. Heitmann
Appl. Opt. 14(11) 2607-2613 (1975)

Fast random access to frequency-selective optical memories

M. Rätsep, M. Tian, I. Lorgeré, F. Grelet, and J.-L. Le Gouët
Opt. Lett. 21(1) 83-85 (1996)

All-optical 10Gb/s ternary-CAM cell for routing look-up table applications

George Mourgias-Alexandris, Christos Vagionas, Apostolos Tsakyridis, Pavlos Maniotis, and Nikos Pleros
Opt. Express 26(6) 7555-7562 (2018)