"Photon Number Resolving, High Speed Detectors and Quantum Light Sources"
Speaker: Dr Thomas Gerrits
National Institute of Standards and Technology
Date: 5 July 2011
Time: 2pm
Venue: Building 53, room 4025
Abstract:
High quantum efficiency (>95%) photon number resolving single detectors are a unique way to fully and unambiguously characterise an optical quantum state. In the past we have generated and measured anapproximation of an optical Schrödinger cat state by photon subtraction from squeezed vacuum. Using the photon-number resolving transition edge sensors (TES), we were able to subtract up to three photons from a squeezed light pulse and generate an optical Schrödinger cat state with fidelity of 0.59 and a size of 2.75photons. Increasing the purity of the squeezing is the key to generating high fidelity cat states at high rates.Therefore, we engineered a squeezing source designed to produce a pure squeezed state. The characterisation of this source was done using the photon-number resolving TES, as well as a high-speed superconducting nanowire detector. Our collaboration with the Optoelectronics Research Centre recently yielded the firstintegrated single photon detector, based on TES technology, on an optical waveguide circuit at telecom wavelengths. This promising result points the path towards scalable on-chip quantum informationapplications in the future.
Biography:
Thomas Gerrits obtained his Ph.D. from the Radboud University in Nijmegen, The Netherlands in 2004. In 2004 he joined the National Institute of Standards and Technology, where since 2006 he is working on theexperimental realisation of optical Schrödinger cat states for quantum information applications and high precision metrology.