title: Ultrafast Thermal Nonlinearity.
abstract: Third order nonlinear optical phenomena explored in the last half century have been predicted to find wide range of applications in many walks of life, such as all-optical switching, routing, and others, yet this promise has not been fulfilled primarily because the strength of nonlinear effects is too low when they are to occur on the picosecond scale required in today's signal processing applications. The strongest of the third-order nonlinearities, engendered by thermal effects, is considered to be too slow for the above applications. In this work we show that when optical fields are concentrated into the volumes on the scale of few tens of nanometers, the speed of the thermo-optical effects approaches picosecond scale. Such a sub-diffraction limit concentration of field can be accomplished with the use of plasmonic effects in metal nanoparticles impregnating the thermo-optic dielectric (e.g. amorphous Si) and leads to phase shifts sufficient for all optical switching on ultrafast scale.
authors.affiliation: Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, Maryland 21218.
authors.forename: Jacob B
authors.initials: JB
authors.lastname: Khurgin
authors.affiliation: Department of Engineering, University of Massachusetts Boston, Boston, Massachusetts 02125.
authors.forename: Greg
authors.initials: G
authors.lastname: Sun
authors.affiliation: Department of Physics, National Taiwan University, Taipei 10617, Taiwan.
authors.forename: Wei Ting
authors.initials: WT
authors.lastname: Chen
authors.affiliation: Department of Physics, National Taiwan University, Taipei 10617, Taiwan.
authors.forename: Wei-Yi
authors.initials: WY
authors.lastname: Tsai
authors.affiliation: Department of Physics, National Taiwan University, Taipei 10617, Taiwan.|Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan.
authors.forename: Din Ping
authors.initials: DP
authors.lastname: Tsai