Photographing by means of a diffractive axicon

TL;DR

This paper demonstrates that a simple compact disc can be used as a diffractive axicon to generate photographic images and act as a spectral filter based on wavelength-dependent focusing.

Contribution

It introduces a novel use of a compact disc as a diffractive optical element for imaging and spectral filtering.

Findings

Compact disc can generate diffraction-free beams.

Image focusing depends on light wavelength.

Compact disc can serve as a spectral filter.

Abstract

In this paper we demonstrate that the light diffracted by a simple compact disc can be used to generate photographic images of a certain kind. Being the compact disc an axicon that generates a diffraction-free beam, we show that the focusing position of an image depends of the wavelength of the diffracted light, what makes possible its use as a spectral filter.