High-efficiency broad-bandwidth sub-wavelength grating based fibre-chip coupler in SOI

TL;DR

This paper presents a detailed analysis and design of subwavelength grating couplers in Silicon-on-Insulator, achieving high efficiency and broad bandwidth for fiber-chip coupling.

Contribution

It introduces optimized subwavelength grating coupler designs with high efficiency and broadband operation, analyzing loss mechanisms and trade-offs.

Findings

Achieved 84% coupling efficiency with 50 nm bandwidth.

Achieved 98% coupling efficiency with 44 nm bandwidth.

Provided design parameters for high-efficiency broadband couplers.

Abstract

We report a comprehensive study on the performance of uniform and non-uniform based subwavelength grating couplers in Silicon-on-Insulator. The two performance metrics, coupling efficiency and bandwidth enhancement and trade-offs is presented. We also present, design parameters to achieve high-efficiency and broadband operation based on the detailed study of various loss mechanisms in the grating. Based on the detailed analysis subwavelength grating coupler designs with efficiency as high as 84 % with a 1 dB bandwidth of 50 nm and 98 % with a 44 nm 1 dB bandwidth is presented.