Abstract
Current silicon waveguide Bragg gratings typically introduce perturbation to the optical mode in the form of modulation of the waveguide width or cladding. However, since such a perturbation approach is limited to weak perturbations to avoid intolerable scattering loss and higher-order modal coupling, it is difficult to produce ultra-wide stopbands. In this Letter, we report an ultra-compact Bragg grating device with strong perturbations by etching nanoholes in the waveguide core to enable an ultra-large stopband with apodization achieved by proper location of the nanoholes. With this approach, a 15 µm long device can generate a stopband as wide as 110 nm that covers the entire ${\rm C} + {\rm L}$ band with a 40 dB extinction ratio and over a 10 dB sidelobe suppression ratio (SSR). Similar structures can be further optimized to achieve higher SSR of $ \gt {17}\;{\rm dB}$ for a stopband of about 80 nm.
© 2020 Optical Society of America
Full Article | PDF ArticleMore Like This
Chenlei Li, Ming Zhang, John E. Bowers, and Daoxin Dai
Opt. Lett. 45(8) 2259-2262 (2020)
Han Yun, Mustafa Hammood, Stephen Lin, Lukas Chrostowski, and Nicolas A. F. Jaeger
Opt. Lett. 44(20) 4929-4932 (2019)
Yu He, Yong Zhang, Ruihuan Zhang, Lu Sun, and Yikai Su
Opt. Lett. 46(2) 194-197 (2021)