On-Chip Low-Power Gray Code Generation Based on Opto-Mechanical Microring Resonators

Li Liu,Yue Yang,Shasha Liao,Jin Yue

doi:10.1109/jphot.2020.2986188

Abstract

We propose and experimentally demonstrate on-chip energy-efficient Gray code generation based on a scalable and compact optical encoder. The operation principle of the integrated encoder is based on the nonlinear effects in silicon opto-mechanical microring resonators (MRRs), which could be excited by ultra-low input powers. By adjusting the input powers with hierarchical power levels, the red-shifts of the MRR transmission spectrum could be flexibly manipulated. In this case, the output powers of the MRR drop-port and through-port could be controllable and switchable to generate different codes. Through tuning the optical encoding powers in a specific rule, 4-bit and 2-bit Gray codes have been successfully demonstrated. The required power of the proposed 4-bit encoder is as low as −6 dBm, which is favorable to build energy-efficient optical encoding systems. To the best of our knowledge, we have realized a nano-mechanical optical encoder with the lowest required power. Moreover, the encoder structure has great scalability, thus 2N-bit Gray code could be generated by utilizing 2N-1 add-drop MRRs. With the dominant advantages of ultra-low power consumption (−6 dBm), compact size (0.08 mm2) and great scalability, the proposed optical encoder has many significant applications in optical encoding and communication chips.

Highlights

Optical logic gates and logic functional devices are fundamental components and long-standing goals in optical communication systems [1]–[3]
We propose and experimentally demonstrate on-chip energy-efficient Gray code generation based on a scalable and compact optical encoder
The operation principle of the integrated encoder is based on the nonlinear effects in silicon opto-mechanical microring resonators (MRRs), which could be excited by ultra-low input powers

Summary

Introduction

Optical logic gates and logic functional devices are fundamental components and long-standing goals in optical communication systems [1]–[3]. The silicon opto-mechanical devices provide an effective solution for low-power optical processing. We experimentally demonstrate optical 4-bit and 2-bit Gray code generation based on the silicon opto-mechanical MRRs. The operation principle of the optical encoder is the nonlinear effects in the free-hanging microrings, whose transmission spectra could be flexibly manipulated by low optical powers. The operation principle of the optical encoder is the nonlinear effects in the free-hanging microrings, whose transmission spectra could be flexibly manipulated by low optical powers In this case, the output powers of the MRR drop-port and through-port could be switchable and controllable to generate different codes. The proposed scheme provides an optical processing approach for Gray code generation with advantages of ultra-low power, compact footprint and great scalability, which is competent for practical applications in on-chip optical communication systems

Operation Principle

Experimental Results

Conclusion