One- and two-dimensional photo-imprinted diffraction gratings for manipulating terahertz waves

TL;DR

This paper presents a method to create reconfigurable terahertz diffraction gratings by photo-imprinting patterns onto a GaAs substrate, enabling dynamic control over terahertz wave manipulation.

Contribution

It introduces a novel photo-imprinting technique using femtosecond laser pulses and digital micromirror devices for reconfigurable terahertz components.

Findings

High-contrast photo-induced patterns can diffract terahertz waves.

Reconfigurable terahertz devices demonstrated with digital micromirror technology.

Potential for dynamic terahertz wave control in various applications.

Abstract

Emerging technology based on artificial materials containing metallic structures has raised the prospect for unprecedented control of terahertz waves through components like filters, absorbers and polarizers. The functionality of these devices is static by the very nature of their metallic or polaritonic composition, although some degree of tunability can be achieved by incorporating electrically biased semiconductors. Here, we demonstrate a photonic structure by projecting the optical image of a metal mask onto a thin GaAs substrate using a femtosecond pulsed laser source. We show that the resulting high-contrast pattern of photo- excited carriers can create diffractive elements operating in transmission. With the metal mask replaced by a digital micromirror device, our photo-imprinted photonic structures provide a route to terahertz components with reconfigurable functionality.