Imaging with two spiral diffracting elements intermediated by a pinhole

TL;DR

This paper explains how pseudoscopic images are formed using spiral diffracting elements and a pinhole under white light, highlighting the role of symmetry and how breaking it produces orthoscopic images.

Contribution

It introduces a novel optical setup with spiral diffracting elements and analyzes the symmetry properties responsible for pseudoscopic and orthoscopic image formation.

Findings

Pseudoscopic images are explained by symmetry properties.

White light illumination enables image projection.

Breaking symmetry yields orthoscopic images.

Abstract

A pseudoscopic (inverted depth) image made with spiral diffracting elements intermediated by a pinhole is explained by its symmetry properties. The whole process is made under common white light illumination and allows the projection of images. The analysis of this projection demonstrates that the images of two objects pointing away longitudinally have the main features of standard pseudoscopic image points. An orthoscopic (normal depth) image has also been obtained with the breaking of the symmetry conditions.