title: Phase modulation in horizontal metal-insulator-silicon-insulator-metal plasmonic waveguides.
abstract: An extremely compact Si phase modulator is proposed and validated, which relies on effective modulation of the real part of modal index of horizontal metal-insulator-Si-insulator-metal plasmonic waveguides by a voltage applied between the metal cover and the Si core. Proof-of-concept devices are fabricated on silicon-on-insulator substrates using standard complementary metal-oxide-semiconductor technology using copper as the metal and thermal silicon dioxide as the insulator. A modulator with a 1-μm-long phase shifter inserted in an asymmetric Si Mach-Zehnder interferometer exhibits 9-dB extinction ratio under a 6-V/10-kHz voltage swing. Numerical simulations suggest that high speed and low driving voltage could be achieved by shortening the distance between the Si core and the n(+)-contact and by using a high-κ dielectric as the insulator, respectively.
authors.affiliation: Institute of Microelectronics, A*STAR (Agency for Science, Technology and Research), 11 Science Park Road, Science Park-II, 117685 Singapore. zhusy@ime.a-star.edu.sg
authors.forename: Shiyang
authors.initials: S
authors.lastname: Zhu
authors.forename: G Q
authors.initials: GQ
authors.lastname: Lo
authors.forename: D L
authors.initials: DL
authors.lastname: Kwong
mesh_terms: D017076:Computer-Aided Design; D004553:Electric Conductivity; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007368:Interferometry / Q000295:instrumentation*; D008670:Metals / Q000737:chemistry*; D008904:Miniaturization; D012825:Silicon / Q000737:chemistry*; D020349:Surface Plasmon Resonance / Q000295:instrumentation*; D013685:Telecommunications / Q000295:instrumentation*
chemical_list: D008670:Metals; D012825:Silicon