Programmable and arbitrary-trajectory ultrafast flying focus pulses

TL;DR

This paper presents a method to design optical setups that generate ultrafast laser pulses with customizable moving focal points along arbitrary paths, enhancing control over laser focus dynamics for advanced applications.

Contribution

It introduces a novel design approach for creating ultrashort flying focus pulses with arbitrary trajectories using specific optical components, enabling flexible and rapid focal control.

Findings

Demonstrated optical configurations for arbitrary-trajectory flying focus pulses

Extended focal range using an axiparabola

Structured radial group delay with a reflective echelon or deformable mirror-SLM pair

Abstract

"Flying focus" techniques produce laser pulses with dynamic focal points that travels distances much greater than a Rayleigh length. The implementation of these techniques in laser-based applications requires the design of optical configurations that can both extend the focal range and structure the radial group delay. This article describes a method for designing optical configurations that produce ultrashort flying focus pulses with arbitrary-trajectory focal points. The method is illustrated by several examples that employ an axiparabola for extending the focal range and either a reflective echelon or a deformable mirror-spatial light modulator pair for structuring the radial group delay. The latter configuration enables rapid exploration and optimization of flying foci, which could be ideal for experiments.