High harmonics with spatially varying ellipticity for spatially-resolved magnetic spectroscopy

Published

April 17, 2018

Author(s)

Daniel D. Hickstein, Jennifer Ellis, Kevin M. Dorney, Nathan J. Brooks, Christian Gentry, Justin M. Shaw, Quynh Nguyen, Christopher A. Mancuso, Henry C. Kapteyn, Margaret M. Murnane, Carlos Hernandez-Garcia

Abstract

In this work, we present a new method to produce ultrashort pulses of circularly polarized extreme ultraviolet light. We combine two orthogonally-polarized high-harmonic sources to produce a far-field beam with a uniform intensity distribution but with a spatially varying ellipticity – ranging from linearly to fully circularly polarized. This spatially varying ellipticity was characterized using extreme ultraviolet magnetic circular dichroism, which demonstrates that a high degree of circularity is achieved, reaching 100% near the magnetic M-edge. Then, by using the unique spatial variation of the ellipticity of this source, we demonstrate that we can measure spectrally-resolved magnetic dichroism without the use of a spectrometer, which facilitates hyperspectral imaging of chiral systems. Through numerical simulations, we also show the generality of this scheme, which can be applied with either discrete harmonic orders, driven by long pulse lasers, or high-harmonic supercontinuua, driven by short laser pulses. Therefore, this technique provides a viable route for the production of bright isolated attosecond pulses with circular polarization that can probe the fastest spin dynamics in materials.

Citation

Optica

Pub Type

Journals

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Keywords

high-harmonic generation, lasers, magnetic dichroism, x-ray

Citation

Hickstein, D. , Ellis, J. , Dorney, K. , Brooks, N. , Gentry, C. , Shaw, J. , Nguyen, Q. , Mancuso, C. , Kapteyn, H. , Murnane, M. and Hernandez-Garcia, C. (2018), High harmonics with spatially varying ellipticity for spatially-resolved magnetic spectroscopy, Optica, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=925070 (Accessed May 10, 2024)