CMOS-Compatible Plasmonic Bragg Reflectors Based on Cu-Dielectric-Si Structures

Abstract

Cu-dielectric-Si hybrid plasmonic waveguide (HPW)-based plasmonic Bragg reflectors (PBRs) are fabricated on an SoI platform using standard CMOS technology and characterized in the 1515-1615-nm wavelength range. Optical stop-bands are experimentally observed, depending on the grating size and the number of grating periods. PBRs with 20 periods exhibit ~ -30-dB transmission within the stop-band, ~ -10-dB transmission outside the stop-band (both are normalized by the corresponding 2- μm-long straight HPW), steep band edges of ~ 0.92 dB/nm, and small ripples in the transmission spectra beyond the band edges, in agreement with those predicted from finite-difference-time-domain simulations. These favorable performances, together with ease fabrication and CMOS compatibility, make the proposed HPW-based PBRs useful for dense Si photonic integrated circuits.