Title | High-efficiency vertical fibre-to-polymer waveguide coupling scheme for scalable polymer photonic circuits |
Publication Type | Journal Article |
Year of Publication | 2021 |
Authors | Kumar, A, Nambiar, S, Kallega, R, Ranganath, P, Ea, P, Selvaraja, SKumar |
Journal | Optics Express |
Volume | 29 |
Pagination | 9699–9710 |
Abstract | Polymer photonic circuits offer a versatile platform for various applications, including communication, sensing and optical signal processing. Though polymers offer broadband, linear and nonlinear optical properties, the coupling between an optical fibre and a polymer waveguide has been a challenge. In this work, we propose and demonstrate a wafer-scale vertical coupling scheme for polymer waveguides. The scheme uses a silicon nitride grating coupler with an inverse taper to couple between an optical fibre and a SU8 polymer waveguide. We demonstrate a maximum coupling efficiency of -3.55 dB in the C-band and -2.92 dB in the L-band with a 3-dB bandwidth of 74 and 80 nm, respectively. A detailed design and simulation, fabrication, and characterisation results are presented. The scheme demonstrates a scalable and efficient surface grating approach for polymer photonic integrated circuits. |