title: Quantum nondemolition measurement of photon number via optical Kerr effect in an ultra-high-Q microtoroid cavity.
abstract: We theoretically investigate a quantum nondemolition (QND) measurement with optical Kerr effect in an ultra-high-Q microtoroidal system. The analytical and numerical results predict that the present QND measurement scheme possesses a high sensitivity, which allows for detecting few photons or even single photons. Ultra-high-Q toroidal microcavity may provide a novel experimental platform to study quantum physics with nonlinear optics at low light levels.
authors.affiliation: Department of Electrical and Systems Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA. yfxiao@ese.wustl.edu
authors.forename: Yun-Feng
authors.initials: YF
authors.lastname: Xiao
authors.forename: Sahin Kaya
authors.initials: SK
authors.lastname: Ozdemir
authors.forename: Venkat
authors.initials: V
authors.lastname: Gaddam
authors.forename: Chun-Hua
authors.initials: CH
authors.lastname: Dong
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Imoto
authors.forename: Lan
authors.initials: L
authors.lastname: Yang