2026/02/13 by Fernando Martín-Romero, Raquel Resta, Òscar Fontelles +2 · 1 voice
Engineering · Materials Science · Physics and Astronomy · #Advanced Fiber Laser Technologies #Graphene research and applications #Plasmonic and Surface Plasmon Research
paper · pdf · doi:10.1021/acsphotonics.5c02651
openalex publication_date 2026/02/13 · openalex created_date 2026/02/14 · openalex updated_date 2026/08/01
High Resolution Image Download MS PowerPoint Slide We present the design, fabrication, and characterization of broadband graphene-silicon nitride integrated mode filters working in the optical C-band, centered at a wavelength of 1.55 μm. The devices presented here prevent modal crosstalk, thus avoiding signal degradation in multimode communication systems. In particular, the fabricated filters are based on a dual-mode silicon nitride waveguide, partially covered by a centered graphene nanoribbon that induces a stronger absorption for the TE 0 mode than for the TE 1 mode. The geometry of the design has been optimized to minimize the length and insertion losses of the device. A complete fabrication process, including the transfer and lithography of commercial graphene, has been developed. A novel approach was introduced during the etching step, which entailed the simultaneous curing of the resist to encapsulate the graphene nanoribbons prior to the deposition of the upper cladding. Finally, transmission through an array of fully fabricated filters of varying lengths was characterized with a measurement setup employing optical fiber coupling. The maximum experimentally measured contrast between the TE 0 and TE 1 modes is 123 dB/cm, achieved at a wavelength of 1569 nm, simultaneously with a minimum loss of −38 dB/cm for the TE 1 mode. Overall, we fully demonstrate an integrated mode filter based on commercial graphene that paves the way for the implementation of integrated multimode optical communication systems.