Quantum light source boosts attosecond science

Dong Hyuk Ko, P. B. Corkum

Alexandra S. Landsman, Ursula Keller

Rostislav M. Arkhipov, Mikhail V. Arkhipov, Nikolay N. Rosanov

Benjamin Scheuer

In the field of attosecond science, photoelectron spectroscopy and interferometry stand as a central topic not only for its ability to characterise attosecond pulses but also for its ability to make time resolved measurements of electron dynamics. This feature allows for its application across the many fields which depend on the behaviour of electrons. For these reasons, there is significant interest in improving these techniques. One such candidate is the implementation of quantum light states to replace the typical coherent light used for interferometry. In the past, this was not possible due to the weakness of quantum light sources. However, recent development has shown that high intensity bright squeezed vacuum sources are possible and can be made to have high enough intensities in order to drive nonlinear processes, which allows for possibilities within attosecond science. For this work, we will begin developing and characterising an intense bright squeezed vacuum source to be used for applications in photoelectron metrology.

Zhejun Jiang, Shengzhe Pan, Jianqi Chen +12 more

Nonlinear optical processes, mediated by multiphoton interactions rather than single-photon response, are routinely exploited to enable a range of light-based functionalities in devices and applications. Nonlinear effects are enhanced through higher intensity fields, which is a limiting strategy owing to potential radiation damage. An alternative strategy relies on the fluctuation redistribution typical of quantum light, but experimental demonstrations at the most fundamental level have been limited. Here we report experimental nonlinear tunnelling ionization of isolated atoms, a pivotal nonlinear process that drives high-harmonic generation and forms the basis of attosecond science, boosted by quantum light -- bright squeezed vacuum (BSV). A BSV light with an average pulse energy of 300 nJ achieves an effective intensity equivalent to that of a coherent light with 7.1 {\textmu}J, demonstrating a more than 20-fold quantum boost in nonlinear effect from BSV light. This boost is revealed by matching the peaks of the photoelectron momentum spectra produced by the BSV and coherent light using angular streaking. Furthermore, we demonstrate control of the effective intensity of the BSV by tuning the correlation function at fixed average pulse energy, establishing a robust method to tailor nonlinear processes via quantum statistics rather than classical intensity scaling. These findings may facilitate the development of quantum-controlled strong-field dynamics using tailored quantum light sources.

Spencer J. Johnson, Colin P. Lualdi, Kristina A. Meier +1 more