Abstract
We demonstrate highly efficient couplers in a two-dimensional grating configuration for a vertical fiber-coupling fabricated in the silicon-on-insulator platform. A combination of sub-wavelength reflectors and blazed gratings enables both high coupling efficiency and vertical grating coupling. We experimentally achieve coupling efficiencies of −2.6 dB at 1544 nm and −3.4 dB at 1536 nm for x- and y-polarized LP01 modes, respectively. The experimental results are in good agreement with the simulated −2.4 dB coupling efficiency for both polarizations at a wavelength of 1550 nm. Simulated and measured crosstalk between two polarizations were −19 dB and <−16 dB, respectively.
Highlights
Silicon-on-insulator (SOI) has become an established platform for photonics
We demonstrate highly efficient couplers in a two-dimensional grating configuration for a vertical fiber-coupling fabricated in the silicon-on-insulator platform
We introduce highly efficient, polarization-splitting 2-D grating couplers, which provide a perfect vertical coupling to a single mode fiber (SMF) by utilizing a blazed sub-wavelength structure
Summary
Silicon-on-insulator (SOI) has become an established platform for photonics. efficient fiber-to-chip coupling is crucial for practical applications. Single polarization grating couplers with experimental coupling efficiencies of higher than 80% [1]–[3] and 70% [4] in tilted and vertical fiber schemes, respectively, have already been demonstrated on a standard SOI platform. We fabricated the 2-D grating on a standard silicon-on-insulator (SOI) platform and measured coupling losses of 2.6 dB and 3.4 dB for x- and y-polarizations, respectively, while simulations predict coupling efficiencies of 58% for each polarizations. We investigate the fabrication tolerances and derive its impact on the center peak shift Such a tilt-free grating coupler makes it easier to align fibers and offers more degree of freedoms to integrate grating couplers on a very small surface. The work published in this paper, is based in part on a 1D grating coupler configuration previously introduced in Ref. [4]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
