Direct characterization of linear-optical networks

TL;DR

This paper presents a straightforward method to fully characterize multimode linear-optical networks using only a laser source and intensity measurements, verified through experiments on a 6x6 fiber-optic network.

Contribution

The authors introduce a novel, efficient technique for directly determining all parameters of a linear-optical network with minimal equipment, enhancing characterization capabilities.

Findings

Successfully characterized a 6x6 fiber-optic network

Verified results with nonclassical two-photon interference

Method requires only standard laser and intensity measurements

Abstract

We introduce an efficient method for fully characterizing multimode linear-optical networks. Our approach requires only a standard laser source and intensity measurements to directly and uniquely determine all moduli and non-trivial phases of the matrix describing a network. We experimentally demonstrate the characterization of a $6{\times}6$ fiber-optic network and independently verify the results via nonclassical two-photon interference.