Light diffraction from a phase grating at oblique incidence in the intermediate diffraction regime

TL;DR

This paper experimentally investigates the diffraction maxima of a phase grating under oblique incidence, deriving equations based on conservation laws and confirming predictions with experiments, with implications for neutron matter wave studies.

Contribution

It provides a theoretical framework for off-plane diffraction maxima positions based solely on energy and momentum conservation, validated by experiments.

Findings

Good agreement between theory and experiment.

Derived equations for diffraction maxima positions.

Discussion on diffraction efficiencies and neutron wave applications.

Abstract

We experimentally characterize the positions of the diffraction maxima of a phase grating on a screen, for laser light at oblique incidence (so-called off-plane diffraction or conical diffraction). We discuss the general case of off-plane diffraction geometries and derive basic equations for the positions of the diffraction maxima, in particular for their angular dependence. In contrast to previously reported work [Jetty et al., Am. J. Phys. 80, 972 (2012)], our reasoning is solely based on energy- and momentum conservation. We find good agreement of our theoretical prediction with the experiment. A detailed discussion of the diffraction maxima positions, the number of diffraction orders, and the diffraction efficiencies is provided. We assess the feasibility of an experimental test of the phenomenon for neutron matter waves.