Attosecond emission delay from atoms and molecules using multi-dimensional XUV interferometry

Abstract Multi-dimensional interferometry of high harmonic generation is demonstrated using an inline Gouy interferometer. The rich data sets acquired with this technique, coupled with its inherent stability, enable robust phase analysis to be performed, allowing the delay in harmonic emission from a range of atomic and molecular gases to be measured relative to harmonic emission from argon with single-digit attosecond precision. Delays of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>78</mml:mn> <mml:mo>±</mml:mo> <mml:mn>6</mml:mn> </mml:mrow> </mml:math> as, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>25</mml:mn> <mml:mo>±</mml:mo> <mml:mn>6</mml:mn> </mml:mrow> </mml:math> as, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mn>30</mml:mn> <mml:mo>±</mml:mo> <mml:mn>3</mml:mn> </mml:mrow> </mml:math> as and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mn>60</mml:mn> <mml:mo>±</mml:mo> <mml:mn>3</mml:mn> </mml:mrow> </mml:math> as relative to emission from argon were measured for Xe, Kr, CO 2 and N 2 , respectively. The scheme can easily be incorporated in other high harmonic experiments, such as tomographic imaging of molecular orbitals, and provides an experimentally simple route towards probing ultrafast dynamics in molecular systems.