Polarization-resolved and polarization- multiplexed spike encoding properties in photonic neuron based on VCSEL-SA

Yahui Zhang,Yue Hao,Xingxing Guo,Aijun Wen,Shuiying Xiang

doi:10.1038/s41598-018-34537-x

Yahui Zhang, Yue Hao + Show 3 more

Open Access

https://doi.org/10.1038/s41598-018-34537-x

Copy DOI

Journal: Scientific Reports	Publication Date: Oct 31, 2018
Citations: 23	License type: open-access

Affiliation: Xidian University

Abstract

The spike encoding properties of two polarization-resolved modes in vertical-cavity surface-emitting laser with an embedded saturable absorber (VCSEL-SA) are investigated numerically, based on the spin-flip model combined with the Yamada model. The results show that the external input optical pulse (EIOP) can be encoded into spikes in X-polarization (XP) mode, Y-polarization (YP) mode, or both XP and YP modes. Furthermore, the numerical bifurcation diagrams show that a lower (higher) strength of EIOP is beneficial for generating tonic (phasic) spikes; a small amplitude anisotropy contributes to wide (narrow) tonic spiking range in XP (YP) mode; a large current leads to low thresholds of EIOP strength for both XP and YP modes. However, the spike encoding properties are hardly affected by the phase anisotropy. The encoding rate is shown to be improved by increasing EIOP strength. Moreover, dual-channel polarization-multiplexed spike encoding can also be achieved in a single VCSEL-SA. To the best of our knowledge, such single channel polarization-resolved and dual-channel polarization-multiplexed spike encoding schemes have not yet been reported. Hence, this work is valuable for ultrafast photonic neuromorphic systems and brain-inspired information processing.

Highlights

Vertical-cavity surface-emitting lasers (VCSELs) are popular candidates for many potential applications, including optical communication, optical signal processing, and optical computation, as they exhibit many advantages, such as low manufacturing cost, easy to integrate into two-dimensional arrays, and high energy efficiency[1,2]
We derive the theoretical model to account for the polarization dynamics, saturable absorber, and external input optical pulse (EIOP) in VCSEL-SA, by combing the well-known spin-flip model (SFM) and Yamada models
The single-channel spike encoding in the polarization-resolved modes and the dual-channel polarization-multiplexed spike encoding in a single VCSEL-SA are investigated numerically

Summary

Introduction

Vertical-cavity surface-emitting lasers (VCSELs) are popular candidates for many potential applications, including optical communication, optical signal processing, and optical computation, as they exhibit many advantages, such as low manufacturing cost, easy to integrate into two-dimensional arrays, and high energy efficiency[1,2]. As can be seen in Fig. 2(a2)–(c2), for case (ii), with different Δτ of EIOP, the EIOP is encoded into one, three, and five spikes in YP mode, respectively, which are similar to the responses in XP mode.

Results

Conclusion