Efficient generation of propagation-invariant spatially-stationary partially coherent fields

TL;DR

This paper introduces a new method to generate propagation-invariant, spatially-stationary partially coherent fields using incoherent mixtures of plane waves from LEDs, with potential applications in holography and imaging.

Contribution

The authors develop a controllable technique for creating propagation-invariant fields with customizable coherence properties using uncorrelated primary sources.

Findings

Successfully generated various spatially-stationary fields including a new 'region-wise' type.

Demonstrated propagation-invariance of the generated fields.

Potential applications in holography, OCT, and turbulence imaging.

Abstract

We propose and demonstrate a novel method for generating propagation-invariant spatially-stationary fields in a controllable manner. Our method relies on producing incoherent mixtures of plane waves using planar primary sources that are spatially completely uncorrelated. The strengths of the individual plane waves in the mixture decide the exact functional form of the generated coherence function. We use LEDs as the primary incoherent sources and experimentally demonstrate the effectiveness of our method by generating several spatially-stationary fields, including a new type, which we refer to as the "region-wise spatially-stationary field." We also experimentally demonstrate the propagation-invariance of these fields, which is an extremely interesting and useful property of such fields. Our work should have important implications for applications that exploit the spatial coherence properties either in a transverse plane or in a propagation-invariant manner, such as correlation holography, wide-field OCT, and imaging through turbulence.