Spatiotemporal control of laser intensity through cross-phase modulation

TL;DR

This paper introduces a novel spatiotemporal control technique called 'flying focus X' that uses cross-phase modulation to shape laser pulses without constraining their profile or orbital angular momentum, enabling advanced laser applications.

Contribution

The paper presents a new method for spatiotemporal pulse shaping that overcomes previous limitations by employing a stencil pulse and cross-phase modulation in a Kerr lens.

Findings

Enables arbitrary-velocity, variable-duration intensity peaks with OAM

Allows any pulse profile or OAM in the primary pulse

Simulations demonstrate long-distance, controlled intensity peaks

Abstract

Spatiotemporal pulse shaping provides control over the trajectory and range of an intensity peak. While this control can enhance laser-based applications, the optical configurations required for shaping the pulse can constrain the transverse or temporal profile, duration, or orbital angular momentum (OAM). Here we present a novel technique for spatiotemporal control that mitigates these constraints by using a "stencil" pulse to spatiotemporally structure a second, primary pulse through cross-phase modulation (XPM) in a Kerr lens. The temporally shaped stencil pulse induces a time-dependent focusing phase within the primary pulse. This technique, the "flying focus X," allows the primary pulse to have any profile or OAM, expanding the flexibility of spatiotemporal pulse shaping for laser-based applications. As an example, simulations show that the flying focus X can deliver an arbitrary-velocity, variable-duration intensity peak with OAM over distances much longer than a Rayleigh range.