Photonic crystal waveguides on silicon rich nitride platform.

Kapil Debnath,Frederic Y Gardes,Thalia Dominguez Bucio,Abdelrahman Al-Attili,Shinichi Saito,Ali Z Khokhar

doi:10.1364/oe.25.003214

Abstract

We demonstrate design, fabrication, and characterization of two-dimensional photonic crystal (PhC) waveguides on a suspended silicon rich nitride (SRN) platform for applications at telecom wavelengths. Simulation results suggest that a 210 nm photonic band gap can be achieved in such PhC structures. We also developed a fabrication process to realize suspended PhC waveguides with a transmission bandwidth of 20 nm for a W1 PhC waveguide and over 70 nm for a W0.7 PhC waveguide. Using the Fabry-Pérot oscillations of the transmission spectrum we estimated a group index of over 110 for W1 PhC waveguides. For a W1 waveguide we estimated a propagation loss of 53 dB/cm for a group index of 37 and for a W0.7 waveguide the lowest propagation was 4.6 dB/cm.

Highlights

A strong light-matter interaction between the optical field and the material medium is essential for a diverse field of applications, ranging from integrated photonics, optical sensing, quantum optics, and nonlinear optics etc
Fabrication, and characterization of two-dimensional photonic crystal (PhC) waveguides on a suspended silicon rich nitride (SRN) platform for applications at telecom wavelengths
Simulation results suggest that a 210 nm photonic band gap can be achieved in such PhC structures

Summary

Introduction

A strong light-matter interaction between the optical field and the material medium is essential for a diverse field of applications, ranging from integrated photonics, optical sensing, quantum optics, and nonlinear optics etc. It has been well established that by using the slow light property of PhC waveguides, light can be propagated through them at a fraction of the speed of light in vacuum [11,12] This ability of PhC waveguides has been exploited for many linear or nonlinear applications, such as electro-optic modulation [2] and optical switching [13], optical delay line [14], signal regeneration through four wave mixing [15,16] and Raman amplification [17] etc. One way to improve the nonlinear coefficient is by increasing the Si content of the nitride film Using such Si-Rich Nitride (SRN), different research groups have demonstrated enhanced nonlinear effects [21,22,23,24]. To realize broadband operation we used a W0.7 PhC waveguide, which showed a transmission band of over 70 nm and propagation loss of 4.6 dB/cm at group index of 7.4 in the fast light region

Methods

Conclusion