Design and investigation of a dual-layer grating coupler for efficient vertical fiber-chip coupling

Abstract

A novel dual-layer grating coupler was designed for efficient vertical coupling between a single-mode fiber and silicon nanowires, with characteristics of polarization diversity and both wavelength bands of 1.3 and 1.55 μm. Theoretical analysis and two-dimensional finite-difference time-domain simulations were applied to verify the performance of the design. Optimized results show that the coupling efficiencies of a dual-port output of 41% (−3.87 dB) for transverse-electric polarization at 1.56 μm, 32.88% (−4.83 dB) for transverse-magnetic (TM) polarization at 1.58 μm, and 27.06% (−5.68 dB) for TM polarization at 1.32 μm can be achieved. Dual-layer Fabry–Perot resonance was also investigated for high coupling efficiency.

Study of an Integration Platform Based on an Adiabatic Active-Layer Waveguide Connection for InP Photonic Device Integration Mirroring That of Heterogeneous Integration on Silicon

“…This method enables the passive photonic devices to be fabricated on the top silicon layer of a Silicon-on-Insulator (SOI) substrate and the active InP-based devices to be fabricated on the bonded epitaxial layer. In addition, typical optical coupling from the passive silicon waveguide to an optical fiber is usually performed with the use of a surface grating [12][13][14]. Aside from its compatibility with silicon photonics, from an active-passive photonic device integration viewpoint, this approach has a few advantages in that the silicon has relatively low optical absorption, so low-loss passive photonic devices can be fabricated.…”

Optical waveguide crossing based on SOI slab waveguides

“…ntegrated optical circuits realized on silicon-on-insulator (SOI) wafers consisting of channel waveguides with silicon (Si) core and silica (SiO 2 ) cladding are promising platform to integrate various optical waveguide devices, such as optical switches, [1][2][3] optical resonators, [4][5][6][7][8] optical directional couplers, [9][10][11] polarization splitters, 12,13) and grating couplers, [14][15][16][17][18] with extremely small size. However, different from multi-layer electrical interconnections used in complementary metal oxide semiconductor (CMOS) integrated circuits, single-layer optical interconnections with channel waveguides are required in standard planer optical circuits.…”