C- and O-Band Dual-Polarization Fiber-to-Chip Grating Couplers for Silicon Nitride Photonics
Abstract
Highly efficient coupling of light from an optical fiber to silicon nitride (SiN) photonic integrated circuits (PICs) is experimentally demonstrated with simple and fabrication-tolerant grating couplers (GC). Fully etched amorphous silicon gratings are formed on top of foundry-produced SiN PICs in a back-end-of-the-line (BEOL) process, which is compatible with 248 nm deep UV lithography. Metallic back reflectors are introduced to enhance the coupling efficiency (CE) from −1.11 to −0.44 dB in simulation and from −2.2 to −1.4 dB in experiments for the TE polarization in the C-band. Furthermore, these gratings can be optimized to couple both TE and TM polarizations with a CE below −3 dB and polarization-dependent losses under 1 dB over a wavelength range of 40 nm in the O-band. This elegant approach offers a simple solution for the realization of compact and, at the same time, highly efficient coupling schemes in SiN PICs. Show more
Permanent link
https://doi.org/10.3929/ethz-b-000638981Publication status
publishedExternal links
Journal / series
ACS PhotonicsVolume
Pages / Article No.
Publisher
American Chemical SocietySubject
integrated photonics; fiber-to-chip coupling; grating; silicon nitride; Chromotography; Manufacturing; Polarization; Silicon; WaveguidesOrganisational unit
03974 - Leuthold, Juerg / Leuthold, Juerg
02635 - Institut für Elektromagnetische Felder / Electromagnetic Fields Laboratory
Funding
871658 - Neuro-augmented 112Gbaud CMOS plasmonic transceiver platform for Intra- and Inter-DCI (EC)
871391 - Energy- and Size-efficient Ultra-fast Plasmonic Circuits for Neuromorphic Computing Architectures (EC)
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