Vectorizing the spatial structure of high-harmonic radiation from gas

F Kong,A Korobenko,Robert W Boyd,D H Ko,T J Hammond,P B Corkum,G G Brown,C Zhang,F Bouchard,Z Li,H Larocque,E Karimi

doi:10.1038/s41467-019-10014-5

Abstract

Strong field laser physics has primarily been concerned with controlling beams in time while keeping their spatial profiles invariant. In the case of high harmonic generation, the harmonic beam is the result of the coherent superposition of atomic dipole emissions. Therefore, fundamental beams can be tailored in space, and their spatial characteristics will be imparted onto the harmonics. Here we produce high harmonics using a space-varying polarized fundamental laser beam, which we refer to as a vector beam. By exploiting the natural evolution of a vector beam as it propagates, we convert the fundamental beam into high harmonic radiation at its focus where the polarization is primarily linear. This evolution results in circularly polarized high harmonics in the far field. Such beams will be important for ultrafast probing of magnetic materials.

Highlights

Strong field laser physics has primarily been concerned with controlling beams in time while keeping their spatial profiles invariant
By exploiting the natural evolution of the vector beam, we convert the fundamental beam into high harmonic radiation at its focus where its polarization is primarily linear
We modify the transverse profile of a Gaussian fundamental beam such that its optical properties vary from one quadrant to another

Summary

Introduction

Strong field laser physics has primarily been concerned with controlling beams in time while keeping their spatial profiles invariant. By exploiting the natural evolution of a vector beam as it propagates, we convert the fundamental beam into high harmonic radiation at its focus where the polarization is primarily linear This evolution results in circularly polarized high harmonics in the far field. To further exploit the spatial degree of freedom, the beam-mixing scheme evolves into the direct modulation of spatial modes of laser beams In this experiment, we use liquid crystal technology[18,19] to shape the polarization of a beam in space rather than in time, which we refer to as a vector beam[20]. By exploiting the natural evolution of the vector beam, we convert the fundamental beam into high harmonic radiation at its focus where its polarization is primarily linear This evolution of the generated high harmonic beam results in circularly polarized XUV radiation in the far field. This opens a field of vectorizing the radiation in both strong infrared and XUV radiation

Methods

Results

Conclusion