On-chip grating coupler array on the SOI platform for fan-in/fan-out of MCFs with low insertion loss and crosstalk.

Yunhong Ding,Christophe Peucheret,Yutaka Miyamoto,Toshio Morioka,Haiyan Ou,Feihong Ye

doi:10.1364/oe.23.003292

Abstract

We report the design and fabrication of a compact multi-core fiber fan-in/fan-out using a grating coupler array on the SOI platform. The grating couplers are fully-etched, enabling the whole circuit to be fabricated in a single lithography and etching step. Thanks to the apodized design for the grating couplers and the introduction of an aluminum reflective mirror, a highest coupling efficiency of -3.8 dB with 3 dB coupling bandwidth of 48 nm and 1.5 dB bandwidth covering the whole C band, together with crosstalk lower than -32 dB are demonstrated.

Highlights

We report the design and fabrication of a compact multi-core fiber fanin/fan-out using a grating coupler array on the SOI platform
The communication capacity of single mode fiber (SMF)-based optical transmission systems has been rapidly pushed towards its theoretical limit [1] by the fast growing traffic demand these years
From the integration point of view, on-chip multi-core fibers (MCFs) couplers are preferred so that many FI/FO couplers and other functionalities such as switching matrices can be integrated on the same chip

Summary

Introduction

The communication capacity of single mode fiber (SMF)-based optical transmission systems has been rapidly pushed towards its theoretical limit [1] by the fast growing traffic demand these years. Space-division multiplexing (SDM) based on multi-core fibers (MCFs) has been demonstrated to be a promising technology to further increase the communication capacity over a single fiber. Traditional free spacebased couplers [6] have been widely used thanks to their high coupling efficiencies with large bandwidths and polarization independence. From the integration point of view, on-chip MCF couplers are preferred so that many FI/FO couplers and other functionalities such as switching matrices can be integrated on the same chip In this context, three dimensional (3D) waveguides fabricated by ultrafast laser inscription [8] have been demonstrated. Low coupling efficiency variation of 1.5 dB between all spatial channels with crosstalk below –32 dB were demonstrated

Grating coupler design

Device fabrication and characterization

Findings

Conclusions