FSR-free add–drop filter based on silicon grating-assisted contradirectional couplers

Abstract

We propose an add–drop filter with an unlimited free spectral range (FSR). The device is based on grating-assisted contradirectional couplers with silicon-on-insulator ridge waveguides. The intrawaveguide coupling is significantly diminished by distancing the periodically structured corrugated waveguide away from the straight input waveguide. Based on this asymmetric structure, calculated results show that the peak reflectivity of the intrawaveguide coupling is lower than 0.1 dB, while that of the contradirectional coupling is higher than 20 dB. An experimental result of 1.8 dB for the intrawaveguide coupling is obtained. A narrow drop-port bandwidth of 0.8 nm is also achieved experimentally.

© 2012 Optical Society of America

Polymer/silica hybrid integration add-drop filter based on grating-assisted contradirectional coupler

Liang Tian, Fei Wang, Yuanda Wu, Yunji Yi, Xiaoqiang Sun, and Daming Zhang
Opt. Lett. 43(10) 2348-2351 (2018)

Broadband flat-top SOI add–drop filters using apodized sub-wavelength grating contradirectional couplers

Han Yun, Mustafa Hammood, Stephen Lin, Lukas Chrostowski, and Nicolas A. F. Jaeger
Opt. Lett. 44(20) 4929-4932 (2019)

Contradirectional couplers in silicon-on-insulator rib waveguides

W. Shi, X. Wang, W. Zhang, L. Chrostowski, and N. A. F. Jaeger
Opt. Lett. 36(20) 3999-4001 (2011)

Subwavelength-grating contradirectional couplers for large stopband filters

Dominique Charron, Jonathan St-Yves, Omid Jafari, Sophie LaRochelle, and Wei Shi
Opt. Lett. 43(4) 895-898 (2018)

Coupler-apodized Bragg-grating add–drop filter

Wei Shi, Han Yun, Charlie Lin, Jonas Flueckiger, Nicolas A. F. Jaeger, and Lukas Chrostowski
Opt. Lett. 38(16) 3068-3070 (2013)