Modifying the optical path in a nonlinear double-slit experiment

TL;DR

This paper investigates a nonlinear double-slit experiment where a nonlinear material alters the optical path, causing a shift in the interference pattern, with a simple model accurately predicting these effects for potential applications in nonlinear material measurement.

Contribution

It introduces a nonlinear interferometric setup based on diffraction with a theoretical model predicting pattern shifts due to nonlinearity.

Findings

Nonlinearity causes a self-induced shift in the interference pattern.

The theoretical model accurately predicts the intensity profile for various parameters.

Potential applications include measuring nonlinear properties of optical materials.

Abstract

In this letter, we study a nonlinear interferometric setup based on diffraction rather than beam combining. It consists of a nonlinear analogue of Young's double-slit experiment where a nonlinear material is placed exactly after one of the slits. The presence of nonlinearity breaks the transverse spatial symmetry of the system and thus modifies the optical path. For moderate nonlinearities this leads to a self-induced shift of the intensity pattern in the transverse plane. A simple theoretical model is developed which is surprisingly accurate in predicting the intensity profile of the main lobes for a wide range of parameters. We discuss about possible applications of our model in nonlinear interferometry, for example in measuring the nonlinearities of optical materials.