Visibility of Young's interference fringes: Scattered light from small ion crystals

TL;DR

This study demonstrates interference patterns in light scattered from small ion crystals, analyzing how laser intensity, ion temperature, and wave-packet localization affect fringe visibility, and uses this to measure coherence properties.

Contribution

It provides a novel experimental approach to measure coherence and interference in light scattered from small ion arrays, linking atomic arrangement with optical coherence.

Findings

Interference fringes observed from 2-4 ion crystals.

Laser intensity influences the visibility of interference fringes.

Control of trapping potential adjusts interatomic distances for structured scattering.

Abstract

We observe interference in the light scattered from trapped $^{40}$Ca$^+$ ion crystals. By varying the intensity of the excitation laser, we study the influence of elastic and inelastic scattering on the visibility of the fringe pattern and discriminate its effect from that of the ion temperature and wave-packet localization. In this way we determine the complex degree of coherence and the mutual coherence of light fields produced by individual atoms. We obtain interference fringes from crystals consisting of two, three and four ions in a harmonic trap. Control of the trapping potential allows for the adjustment of the interatomic distances and thus the formation of linear arrays of atoms serving as a regular grating of microscopic scatterers.