Subwavelength Grating Metamaterial Waveguides and Ring Resonators on a Silicon Nitride Platform

• Published in: Laser & photonics reviews 2023-02, Vol.17 (2), p.n/a
• Main Authors: Naraine, Cameron M., Westwood‐Bachman, Jocelyn N., Horvath, Cameron, Aktary, Mirwais, Knights, Andrew P., Schmid, Jens H., Cheben, Pavel, Bradley, Jonathan D. B.
• Format: Article
• Language: English
• Subjects: Electron beam lithography; Integrated circuits; integrated photonics; Metamaterials; Prototyping; Resonators; ring resonators; Silicon nitride; subwavelength gratings; Waveguides
• ISSN: 1863-8880; 1863-8899
• DOI: 10.1002/lpor.202200216

Subwavelength grating (SWG) metamaterial waveguides and ring resonators on a silicon nitride platform are proposed and demonstrated. The SWG waveguide is engineered such that a large overlap of 53% of the Bloch mode with the top cladding material is achieved, demonstrating excellent potential for applications in evanescent field sensing and light amplification. The devices, which have critical dimensions greater than 100 nm, are fabricated using a commercial rapid turn‐around silicon nitride prototyping foundry process using electron beam lithography. Experimental characterization of the fabricated device reveals excellent ring resonator internal quality factor (2.11 × 105) and low propagation loss (≈1.5 dB cm−1) in the C‐band, a significant improvement of both parameters compared to silicon‐based SWG ring resonators. These results demonstrate the promising prospects of SWG metamaterial structures for silicon nitride based photonic integrated circuits. Silicon nitride‐based subwavelength grating metamaterial waveguides and ring resonators are demonstrated. The devices are fabricated using a commercial rapid prototyping foundry process and exhibit an internal quality factor of 2.11 × 105 and propagation loss of ≈1.5 dB cm−1 in the C‐band. This opens promising prospects for subwavelength grating metamaterial engineering in silicon nitride integrated photonic devices.