Interference Fringes Controlled by Non-Interfering Photons

TL;DR

This paper demonstrates that interference fringes can be controlled by a third, non-interfering photon beam through induced coherence, revealing a new way to manipulate quantum interference patterns.

Contribution

It introduces a novel method of controlling interference fringes using a third beam via induced coherence without emission, expanding understanding of quantum interference phenomena.

Findings

Interference fringes depend on the alignment of a third beam.

The pattern is characterized by an equivalent wavelength combining involved beams.

Control of fringes is achieved without direct interference of the controlling beam.

Abstract

We observe spatial fringes in the interference of two beams, which are controlled by a third beam through the phenomenon of induced coherence without induced emission. We show that the interference pattern depends on the alignment of this beam in an analogous way as fringes created in a traditional division-of-amplitude interferometer depend on the relative alignment of the two interfering beams. We demonstrate that the pattern is characterized by an equivalent wavelength, which corresponds to a combination of the wavelengths of the involved physical light beams.