Frequency converter implementing an optical analogue of the cosmological redshift

TL;DR

This paper demonstrates an optical analogue of cosmological redshift using a dielectric metamaterial with time-varying properties, enabling controlled frequency shifts of electromagnetic waves without sideband generation.

Contribution

It introduces a novel optical frequency converter based on transformation optics that mimics cosmological redshift within a dielectric metamaterial.

Findings

Theoretically shows perfect redshift and blueshift of light in the device.

Uses transformation optics to simulate Robertson-Walker metric.

Achieves frequency shifting without sideband creation.

Abstract

According to general relativity, the frequency of electromagnetic radiation is altered by the expansion of the universe. This effect--commonly referred to as the cosmological redshift--is of utmost importance for observations in cosmology. Here we show that this redshift can be reproduced on a much smaller scale using an optical analogue inside a dielectric metamaterial with time-dependent material parameters. To this aim, we apply the framework of transformation optics to the Robertson-Walker metric. We demonstrate theoretically how perfect redshifting or blueshifting of an electromagnetic wave can be achieved without the creation of sidebands with a device of finite length.