Integrated photonics with programmable non-volatile memory.

Jun-Feng Song,Chao Li,Ying Huang,Lian-Xi Jia,Xiao-Guang Tu,Xian-Shu Luo,Qing Fang,Andy Eu-Jin Lim,Guo-Qiang Lo,Hai-Feng Zhou,Tsung-Yang Liow

doi:10.1038/srep22616

Abstract

Silicon photonics integrated circuits (Si-PIC) with well-established active and passive building elements are progressing towards large-scale commercialization in optical communications and high speed optical interconnects applications. However, current Si-PICs do not have memory capabilities, in particular, the non-volatile memory functionality for energy efficient data storage. Here, we propose an electrically programmable, multi-level non-volatile photonics memory cell (PMC) fabricated by standard complementary-metal-oxide-semiconductor (CMOS) compatible processes. A micro-ring resonator (MRR) was built using the PMC to optically read the memory states. Switching energy smaller than 20 pJ was achieved. Additionally, a MRR memory array was employed to demonstrate a four-bit memory read capacity. Theoretically, this can be increased up to ~400 times using a 100 nm free spectral range broadband light source. The fundamental concept of this design provides a route to eliminate the von Neumann bottleneck. The energy-efficient optical storage can complement on-chip optical interconnects for neutral networking, memory input/output interfaces and other computational intensive applications.

Highlights

Computers have deeply impacted our daily lives in various fields and greatly improved the quality of life[1]
The photonics memory cell (PMC) is programmed by applying a positive voltage on the control gate, while the drain and source are grounded
Power consumption can be reduced by decreasing the ON state wavelength shift from the OFF state and shrinking the micro-ring resonator (MRR) size

Summary

Introduction

Computers have deeply impacted our daily lives in various fields and greatly improved the quality of life[1]. Optical interconnection addresses the data bandwidth limitations faced by copper lines[2], and silicon photonics have been a leading technology solution in this field[3,4,5,6,7,8,9,10]. A non-volatile integrated optical memory on the PIC is a natural progression to enhance memory storage functionality for optical interconnects of the paradigm in applications such as high performance computing[11,12] and neural networking[13]. For process compatibility with the Si-PIC, a CMOS-compatible technology is generally preferred Along this line, a silicon photonics with electrically erasable programmable read-only memory was suggested with simulated results to determine its feasibility[23]. This letter bridges the existing gap by proposing a photonics memory cell (PMC) for memory functionality in silicon photonics

Methods

Results

Conclusion