Broadband phase-preserved optical elevator

TL;DR

This paper demonstrates a broadband, phase-preserving optical elevator using a natural birefringent crystal, enabling virtual lifting of a plane without phase distortion across visible wavelengths.

Contribution

It introduces a practical, broadband optical elevator design based on transformation optics with natural materials, avoiding complex nano-fabrication and narrowband metamaterials.

Findings

Phase is preserved during lifting across 400-700 nm wavelengths.

The device can camouflage objects and operate in different media.

It opens new possibilities for light trapping and optical illusions.

Abstract

Phase-preserved optical elevator is an optical device to lift up an entire plane virtually without distortion in light path or phase. Using transformation optics, we have predicted and observed the realization of such a broadband phase-preserved optical elevator, made of a natural homogeneous birefringent crystal without resorting to absorptive and narrowband metamaterials involving time-consuming nano-fabrication. In our demonstration, the optical elevator is designed to lift a sheet upwards, and the phase is verified to be preserved always. The camouflage capability is also demonstrated in the presence of adjacent objects of the same scale at will. The elevating device functions in different surrounding media over the wavelength range of 400-700 nm. Our work opens up prospects for studies of light trapping, solar energy, illusion optics, communication, and imaging.