title: Ultrasensitive N-photon interferometric autocorrelator.
abstract: We demonstrate a novel method to measure Nth-order (N=1,2,3,4) interferometric autocorrelation with high sensitivity and temporal resolution. It is based on the combination of linear absorption and nonlinear detection in a superconducting nanodetector, providing much higher efficiency than methods based on all-optical nonlinearities. Its temporal resolution is only limited by the quasiparticle energy relaxation time, which is directly measured to be in the 20 ps range for the NbN films used in this work. We present a general model of interferometric autocorrelation with these nonlinear detectors and discuss the comparison with other approaches and possible improvements.
authors.affiliation: COBRA Research Institute, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands. z.zhou@tue.nl
authors.forename: Zili
authors.initials: Z
authors.lastname: Zhou
authors.forename: Giulia
authors.initials: G
authors.lastname: Frucci
authors.forename: Francesco
authors.initials: F
authors.lastname: Mattioli
authors.forename: Alessandro
authors.initials: A
authors.lastname: Gaggero
authors.forename: Roberto
authors.initials: R
authors.lastname: Leoni
authors.forename: Saeedeh
authors.initials: S
authors.lastname: Jahanmirinejad
authors.forename: Thang Ba
authors.initials: TB
authors.lastname: Hoang
authors.forename: Andrea
authors.initials: A
authors.lastname: Fiore