Programmable discriminator of coherent states - experimental realization

TL;DR

This paper presents an experimental optical system that unambiguously identifies one of two non-orthogonal coherent states using interference, confirming theoretical predictions and adaptable for more states.

Contribution

It demonstrates a programmable optical discriminator for coherent states with experimental validation, extending previous theoretical proposals.

Findings

Experimental setup confirms theoretical predictions.

System successfully discriminates between two non-orthogonal states.

Setup can be extended for more program states.

Abstract

The optical implementation of the recently proposed unambiguous identification of coherent states is presented. Our system works as a programmable discriminator between two, in general non-orthogonal weak coherent states. The principle of operation lies in the interference of three light beams - two program states and one unknown coherent state which can be equal to whichever of the two program states. The experiment is based on fiber optics. Its results confirm theoretical predictions and the experimental setup can be straightforwardly extended for higher numbers of program states.