Investigation of Electric Field Induced Mixing in Silicon Micro Ring Resonators

Francesco De Leonardis,Vittorio M N Passaro,Richard A Soref

doi:10.1038/s41598-017-03485-3

Abstract

In this paper we present a detailed theoretical investigation of the electric field induced mixing effect, in which the up and down frequency-conversion processes are obtained by inducing an effective second order susceptibility via the periodic spatial distribution of reversed biased p-i-n junctions. The possibility of realizing a frequency generation process within an integrated microring resonator is demonstrated here, by simulations, in the silicon on insulator platform. Furthermore, general physical features have been investigated by means of a comparative analysis of the frequency generation performance as a function of the input pump power, the linear and nonlinear losses, and the coupling factors. A conversion efficiency of 627.5 %/W has been obtained for the second harmonic generation process. Therefore, an improvement of 4 to 50 times with respect to the straight waveguides is achieved, depending on the cavity ring radius. Finally, for the up/down conversion, from telecom idler to mid-IR and from Mid-IR to telecom signal, respectively, an efficiency of 85.9%/W and 454.4 %/W has been obtained in the silicon microring resonator, respectively.

Highlights

The Pockels effect has been experimentally and theoretically demonstrated in strained silicon14–16 as a promising candidate for realizing optical modulators and switches
Quasi-phase matching between the pump and second harmonic modes is achieved by controlling the spatial distribution of the direct current (DC) field, and of χ(2), via periodic distribution of reverse-biased p-i-n junctions
We have considered the case proposed in ref. 22, where the electric field-induced second harmonic generation (EFISHG) is induced in a silicon ridge waveguide

Summary

Introduction

The Pockels effect has been experimentally and theoretically demonstrated in strained silicon as a promising candidate for realizing optical modulators and switches. Second-Harmonic-Generation (SHG) experiments and first-principle calculations have been carried out at optical wavelengths in a Si waveguide by using a stressing silicon nitride overlayer . We theoretically investigate the Electric Field Induced Mixing (EFIM) effect in SOI waveguides, which is three-wave mixing (TWM) wherein the sum and difference frequency generation is obtained via an electric-field-induced χ(2). The validation of the proposed model is reported, where a comparison with experimental results is performed in the case of the second harmonic generation process induced in straight waveguides. The theoretical calculations for the second harmonic generation and frequency conversion processes in SOI microring resonators are reported in Section 3.2 and 3.3, respectively.

Objectives

Methods

Results

Conclusion