Optical bistability in a one-dimensional photonic crystal resonator using a reverse-biased pn-junction.

Majid Sodagar,Ali A Eftekhar,Mehdi Miri,Ali Adibi

doi:10.1364/oe.23.002676

Abstract

Optical bistability provides a simple way to control light with light. We demonstrate low-power thermo-optical bistability caused by the Joule heating mechanism in a one-dimensional photonic crystal (PC) nanobeam resonator with a moderate quality factor (Q ~8900) with an embedded reverse-biased pn-junction. We show that the photocurrent induced by the linear absorption in this compact resonator considerably reduces the threshold optical power. The proposed approach substantially relaxes the requirements on the input optical power for achieving optical bistability and provides a reliable way to stabilize the bistable features of the device.

Highlights

Use of nonlinear properties of optical materials is inevitable for all-optical signal processing applications [1]
We demonstrate low-power thermal-bistability in Si photonic resonators with moderate Qs (e.g., 10 K) based on amplification of the heat generated by linear absorption using Joule-heating [14]
We demonstrated here an optical bistable device in a Si-based integrated photonic platform comprising a rather low-Q photonic crystal (PC) nanobeam resonator with an embedded pn-junction

Summary

Introduction

Use of nonlinear properties of optical materials is inevitable for all-optical signal processing applications [1]. In both cases of thermal bistability, the threshold field density in the resonator is very high This severely limits the use of optical bistability to form practical nonlinear integrated photonic devices in Si. In this paper, we demonstrate low-power thermal-bistability in Si photonic resonators with moderate Qs (e.g., 10 K) based on amplification of the heat generated by linear absorption using Joule-heating [14]. The illumination of the depletion region of the pn-junction by the incident light results in photo-generated carriers through linear absorption in Si, and these carriers are swept by the electric field (due to the reverse bias) and are collected at the two sides of the pn-junction device [15,16,17,18] Such photocurrent, though small, once accompanied by a large reverse bias can considerably increase the generated heat per absorbed photon through Joule-heating to considerably reduce the optical power threshold for achieving optical bistability. These gratings are designed using the conventional techniques and for the sole purpose of characterizing the device

Fabrication

Characterization

Discussion

Conclusion