Silicon photonic bandpass filter based on apodized subwavelength grating with high suppression ratio and short coupling length.

Boyu Liu,Yu He,Xinhong Jiang,Yong Zhang,Yikai Su,Ciyuan Qiu,Jizong Peng

doi:10.1364/oe.25.011359

Abstract

A compact silicon bandpass filter with high sidelobe suppression is proposed and experimentally demonstrated using an apodized subwavelength grating (SWG) coupler. The device is implemented by placing a SWG waveguide next to a strip waveguide, and apodization is employed with a Gaussian profile to taper the gap between the two waveguides. A high sidelobe suppression ratio of 27 dB can be obtained with a 3-dB bandwidth of 8.8 nm and an insertion loss of 2.5 dB. Owing to the large optical phase mismatch between the two waveguides and the presence of the SWG waveguide, the coupling length of the device is reduced to 100.3 μm. The experimental results validate our proposed apodized-SWG-based contradirectional coupler (contra-DC) as a promising device in suppressing out-of-band components in coarse wavelength division multiplexed (CWDM) optical communication systems.

Highlights

Ever-increasing network capacity for broadband access is driving the demand for highperformance filtering technologies in coarse wavelength division multiplexed (CWDM) optical communication networks [1,2,3,4,5]
The device is implemented by placing a subwavelength grating (SWG) waveguide next to a strip waveguide, and apodization is employed with a Gaussian profile to taper the gap between the two waveguides
A high sidelobe suppression ratio of 27 dB can be obtained with a 3-dB bandwidth of 8.8 nm and an insertion loss of 2.5 dB

Summary

Introduction

Ever-increasing network capacity for broadband access is driving the demand for highperformance filtering technologies in coarse wavelength division multiplexed (CWDM) optical communication networks [1,2,3,4,5].

Results

Conclusion