Ultra-compact synthesis of space-time wave packets

TL;DR

This paper introduces a highly compact system for synthesizing space-time wave packets using a novel chirped volume Bragg grating, significantly reducing size and complexity compared to traditional free-space optical setups.

Contribution

The authors develop a miniaturized optical device employing a rotated chirped volume Bragg grating for efficient space-time wave packet synthesis without free-space propagation.

Findings

Achieved space-time wave packet synthesis in a device volume of 25x25x8 mm3.

Eliminated the need for free-space propagation or collimation in the synthesis process.

Demonstrated a compact, alignment-free approach to generating space-time wave packets.

Abstract

Space-time wave packets (STWPs) are pulsed fields in which a strictly prescribed association between the spatial and temporal frequencies yields surprising and useful behavior. However, STWPs to date have been synthesized using bulky free-space optical systems that require precise alignment. We describe a compact system that makes use of a novel optical component: a chirped volume Bragg grating that is rotated by 45 degrees with respect to the plane-parallel device facets. By virtue of this grating's unique structure, cascaded gratings resolve and recombine the spectrum without free-space propagation or collimation. We produce STWPs by placing a phase plate that spatially modulates the resolved spectrum between such cascaded gratings, with a device volume of 25x25x8 mm3, which is orders of magnitude smaller than previous arrangements.