Spatiotemporal differentiators generating optical vortices with transverse orbital angular momentum and detecting sharp change of pulse envelope

TL;DR

This paper introduces a compact spatiotemporal differentiator that generates optical vortices with transverse orbital angular momentum and detects sharp pulse envelope changes, advancing optical manipulation techniques.

Contribution

A novel one-dimensional nanostructure device is proposed to generate and detect spatiotemporal optical vortices with transverse orbital angular momentum.

Findings

Successfully generates STOVs with transverse orbital angular momentum.

Enables detection of sharp pulse envelope changes via interference.

Device is more compact than traditional pulse shapers.

Abstract

As a new degree of freedom for optical manipulation, recently spatiotemporal optical vortices (STOVs) carrying transverse orbital angular momentums have been experimentally demonstrated with pulse shapers. Here a spatiotemporal differentiator is proposed to generate STOVs with transverse orbital angular momentum. In order to create phase singularity in the spatiotemporal domain, the spatiotemporal differentiator is designed by breaking spatial mirror symmetry. In contrast to pulse shapers, the device proposed here is a simple one-dimensional periodic nanostructure and thus it is much more compact. For a normal incident pulse, the differentiator generates a transmitted STOV pulse with transverse orbital angular momentum. Furthermore, the interference of the generated STOVs can be used to detect the sharp changes of pulse envelopes, in both spatial and temporal dimensions.