Compact bends for multi-mode photonic crystal waveguides with high transmission and suppressed modal crosstalk

Victor Liu,Shanhui Fan

doi:10.1364/oe.21.008069

Abstract

We demonstrate an extremely compact bend for a photonic crystal waveguide supporting three spatial modes. The bend exhibits nearly 100% transmission over a relative bandwidth of 1% with less than 1% crosstalk. We show that our design is robust with respect to fabrication errors. Our design method is applied to create a structure consisting of dielectric rods, as well as a structure consisting of air holes in a dielectric background.

Highlights

The use of multiple spatial modes is gaining interest for increasing the throughput of optical information processing systems [1]
Recent work on transformation optics approaches has achieved a waveguide bend structure with high transmission and low crosstalk, but the device has a spatial extent of many wavelengths [4]
In this paper we present the design of a bend for a photonic crystal waveguide supporting three modes with nearly total transmission and almost no crosstalk

Summary

Introduction

The use of multiple spatial modes is gaining interest for increasing the throughput of optical information processing systems [1]. A basic component for integrated systems is a waveguide bend that can simultaneously redirect multiple spatial modes with near total transmission for each mode and low crosstalk between the modes. Recent work on transformation optics approaches has achieved a waveguide bend structure with high transmission and low crosstalk, but the device has a spatial extent of many wavelengths [4]. In integrated 2D photonic crystal systems, the design of bends for single-mode waveguides has been extensively studied both theoretically [5,6,7,8,9] and experimentally [10,11,12,13,14,15]. In this paper we present the design of a bend for a photonic crystal waveguide supporting three modes with nearly total transmission and almost no crosstalk. The physical size of the bend is less than 3 wavelengths long on a side

Methods

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Discussion

Conclusion