title: Terahertz all-optical modulation in a silicon-polymer hybrid system.
abstract: Although gigahertz-scale free-carrier modulators have been demonstrated in silicon, intensity modulators operating at terahertz speeds have not been reported because of silicon's weak ultrafast nonlinearity. We have demonstrated intensity modulation of light with light in a silicon-polymer waveguide device, based on the all-optical Kerr effect-the ultrafast effect used in four-wave mixing. Direct measurements of time-domain intensity modulation are made at speeds of 10 GHz. We showed experimentally that the mechanism of this modulation is ultrafast through spectral measurements, and that intensity modulation at frequencies in excess of 1 THz can be obtained. By integrating optical polymers through evanescent coupling to silicon waveguides, we greatly increase the effective nonlinearity of the waveguide, allowing operation at continuous-wave power levels compatible with telecommunication systems. These devices are a first step in the development of large-scale integrated ultrafast optical logic in silicon, and are two orders of magnitude faster than previously reported silicon devices.
authors.affiliation: Department of Applied Physics, California Institute of Technology, 1200 E California Blvd, Pasadena, CA 91125, USA. hochberg@caltech.edu
authors.forename: Michael
authors.initials: M
authors.lastname: Hochberg
authors.forename: Tom
authors.initials: T
authors.lastname: Baehr-Jones
authors.forename: Guangxi
authors.initials: G
authors.lastname: Wang
authors.forename: Michael
authors.initials: M
authors.lastname: Shearn
authors.forename: Katherine
authors.initials: K
authors.lastname: Harvard
authors.forename: Jingdong
authors.initials: J
authors.lastname: Luo
authors.forename: Baoquan
authors.initials: B
authors.lastname: Chen
authors.forename: Zhengwei
authors.initials: Z
authors.lastname: Shi
authors.forename: Rhys
authors.initials: R
authors.lastname: Lawson
authors.forename: Phil
authors.initials: P
authors.lastname: Sullivan
authors.forename: Alex K Y
authors.initials: AK
authors.lastname: Jen
authors.forename: Larry
authors.initials: L
authors.lastname: Dalton
authors.forename: Axel
authors.initials: A
authors.lastname: Scherer