Photoelectronic mapping of spin-orbit interaction of intense light fields

TL;DR

This paper demonstrates in-situ control and visualization of spin-orbit interaction in intense light fields, revealing how orbital angular momentum converts to spin in strong laser-matter interactions, with implications for ultrafast optics.

Contribution

It introduces a method to modulate and image orbital-to-spin conversion in high-intensity femtosecond laser pulses, advancing understanding of spin-orbit dynamics under extreme conditions.

Findings

Orbital angular momentum can be controllably transformed into spin after focusing.

Orbital-to-spin conversion can be imaged via photoelectron momentum distributions.

Control of spin-orbit dynamics impacts photoelectron holography and EUV radiation.

Abstract

The interaction between a quantum particle's spin angular momentum and its orbital angular momentum is ubiquitous in nature. In optics, the spin-orbit optical phenomenon is closely related with the light-matter interaction and has been of great interest. With the development of laser technology, the high-power and ultrafast light sources now serve as a crucial tool in revealing the behaviour of matters under extreme conditions. The comprehensive knowledge of the spin-orbit interaction for the intense light is of utmost importance. Here, we achieve the in-situ modulation and visualization of the optical orbital-to-spin conversion in strong-field regime. We show that, through manipulating the morphology of femtosecond cylindrical vector vortex pulses by a slit, the photons' orbital angular momentum can be controllably transformed into spin after focusing. By employing strong-field ionization experiment, the orbital-to-spin conversion can be imaged and measured through the photoelectron momentum distributions. Such detection and consequent control of spin-orbit dynamics of intense laser fields have implications on controlling the photoelectron holography and coherent extreme ultraviolet radiation.