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Conference on Lasers and Electro-Optics

Temporal Mode Selective Measurement and Purification of Quantum Light

John M. Donohue, Vahid Ansari, Markus Allgaier, Linda Sansoni, Georg Harder, Jonathan Roslund, Nicolas Treps, Benjamin Brecht, Christine Silberhorn

Published Jan 1, 2018• 0 citations
Publisher

Abstract

We employ dispersion-engineered sum-frequency generation to perform temporal-mode selective measurements on quantum light, provably manipulating the structure of multimode downconverted light and demonstrating spectral-phase sensitive seven-dimensional time-frequency quantum state tomography.
DOI
10.1364/cleo_qels.2018.fw4f.1

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The temporal-mode (TM) basis is a prime candidate to perform high-dimensional quantum encoding. Quantum frequency conversion has been employed as a tool to perform tomographic analysis and manipulation of ultrafast states of quantum light necessary to implement a TM-based encoding protocol. While demultiplexing of such states of light has been demonstrated in the quantum pulse gate (QPG), a multiplexing device is needed to complete an experimental framework for TM encoding. In this work we demonstrate the reverse process of the QPG. A dispersion-engineered difference frequency generation in nonlinear optical waveguides is employed to imprint the pulse shape of the pump pulse onto the output. We study experimentally the process by spectrally shaping the first five orders of Hermite-Gauss modes of various bandwidths. Finally, we establish and model the limits of practical, reliable spectral pulse shaping operation.