Refractive index engineering represents a powerful technique to design devices with advanced characteristics in the silicon-on-insulator platform. The use of subwavelength grating waveguides (SWG), in which subwavelength periodicities in both longitudinal direction and transversal direction are exploited, has shown to be a simple way to tune the desired refractive index. In this work is theoretically carried out the design of different SWG based Bragg grating filters for TE and TM polarization optimized at wavelength 1550 nm and assuming a minimum feature size of 100 nm. The main novelty of the proposed topology is the utilization of wide waveguides, which allow us to effectively control the size of the band gap. Additionally, the resultant quasi-2D structure can be efficiently analyzed by using simpler 2D simulators. Bragg grating filter optimized for TE polarization achieves a band-gap of 100 nm and radiation losses below -20 dB. In contrast, TM polarized waves are able to achieve radiation losses as low as -35 dB and band gap of 18 nm.
Grating couplers are one of the most used elements for coupling of light between optical fibers and photonic integrated components. Silicon–on–insulator platform provides strong confinement of light and allows high integration. In this work, using simulations we have designed a broadband silicon nitride surface grating coupler. The Fourier–eigenmode expansion and finite difference time domain methods are utilized in design optimization of grating coupler structure. The fully, single etch step grating coupler is based on a standard silicon–on–insulator wafer with 0.55 μm waveguide Si3N4 layer. The optimized structure at 1550 nm wavelength yields a peak coupling efficiency –2.6635 dB (54.16%) with a 1–dB bandwidth up to 80 nm. It is promising way for low-cost fabrication using complementary metal–oxide– semiconductor fabrication process.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.