Direct temporal mode measurement for the characterization of temporally multiplexed high dimensional quantum entanglement in continuous variables

TL;DR

This paper introduces a novel method for directly measuring the exact temporal modes of optical fields, enabling precise mode-orthogonal detection and demonstrating temporally multiplexed high-dimensional quantum entanglement in continuous variables.

Contribution

The paper presents a new technique for directly characterizing temporal modes, facilitating mode-matched detection and advancing quantum information processing capabilities.

Findings

Successfully measured the exact temporal modes of optical fields.

Demonstrated temporally multiplexed multi-dimensional quantum entanglement.

Enabled mode-orthogonal homodyne detection in telecom wavelengths.

Abstract

Field-orthogonal temporal mode analysis of optical fields is recently developed for a new framework of quantum information science. But so far, the exact profiles of the temporal modes are not known, which makes it difficult to achieve mode selection and de-multiplexing. Here, we report a novel method that measures directly the exact form of the temporal modes. This in turn enables us to make mode-orthogonal homodyne detection with mode-matched local oscillators. We apply the method to a pulse-pumped, specially engineered fiber parametric amplifier and demonstrate temporally multiplexed multi-dimensional quantum entanglement of continuous variables in telecom wavelength. The temporal mode characterization technique can be generalized to other pulse-excited systems to find their eigen modes for multiplexing in temporal domain.