R&D: Heterogeneous III-V/Si Micro-ring Laser Array with Multi-state NVM for Ternary Content-addressable Memories

Nature Communications has published an article written by Stanley Cheung, Hewlett Packard Labs, Hewlett Packard Enterprise, Milpitas, CA, USA, and Department of Electrical and Computer Engineering, North Carolina State University, Raleigh, NC, USA, Yanir London, Hewlett Packard Labs, Hewlett Packard Enterprise, Milpitas, CA, USA, Yuan Yuan, Hewlett Packard Labs, Hewlett Packard Enterprise, Milpitas, CA, USA, and Department of Electrical and Computer Engineering, Northeastern University, Oakland, CA, USA, Bassem Tossoun, Yiwei Peng, Yingtao Hu, Thomas Van Vaerenbergh, Hewlett Packard Labs, Hewlett Packard Enterprise, Milpitas, CA, USA , Di Liang, Department of Electrical and Computer Engineering, University of Michigan, Ann Arbor, MI, USA , Chong Zhang, Nexus Photonics, Goleta, CA, USA, Geza Kurczveil, and Raymond G. Beausoleil, Hewlett Packard Labs, Hewlett Packard Enterprise, Milpitas, CA, USA.

Abstract: “In this work, we introduce programmable memory elements embedded within III-V/Si light sources which facilitate non-volatile wavelength tuning. These non-volatile III-V/Si micro-ring lasers (MRLs) exhibit non-volatile wavelength shifts of  ~80 pm with  ~40 dB signal extinction ratio while consuming 0 electrical static tuning power. An array of 5 cascaded MRLs is demonstrated with each laser capable of 4 programmable non-volatile states, thus yielding 1024 unique states altogether. Write/erase operations were performed up to 100 cycles with non-volatile time duration lasting up to 24 h. These non-volatile lasers are used to demonstrate optical ternary content-addressable memories (O-TCAM) which can find utility in fast memory search and in-memory computing functions necessary for various machine learning algorithms. The end-to-end energy consumption of the non-volatile MRL O-TCAM with 5 ternary symbols is 1156 fJ/sym. This work provides an opportunity for realizing photonic memory applications in next generation non-volatile photonic systems.“