Ultra compact Bragg grating devices with broadband selectivity

Journal Article · Tue Jan 28 00:00:00 EST 2020 · Optics Letters

DOI:https://doi.org/10.1364/OL.384688· OSTI ID:1594209

Li, Ang ; Davis, Jordan ; Fainman, Yeshaiahu

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 $\mathrm{C}+\mathrm{L}$ 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 $>\; <\#comment/>17\mathrm{d}\mathrm{B}$ for a stopband of about 80 nm.

• Sponsoring Organization: USDOE Advanced Research Projects Agency - Energy (ARPA-E)
• Grant/Contract Number: LEED: A Lightwave Energy-Efficient Datacenter
• OSTI ID: 1594209
• Journal Information: Optics Letters, Journal Name: Optics Letters Vol. 45 Journal Issue: 3; ISSN 0146-9592
• Publisher: Optical Society of America
• Country of Publication: United States
• Language: English