Dr. Michaël Hemmer is an ICFO Alum who was a Research Fellow in the Attoscience and Ultrafast Optics group led by ICREA Professor at ICFO Dr. Jens Biegert from 2011-2014.  ICFOnians are encouraged to come hear about his current work and to reconnect.

ABSTRACT:

Since its inception over 60 years ago, the laser once deemed a solution without a problem has become a ubiquitous tool in area as diverse as advanced manufacturing, health and science. Nowadays, laser systems routinely produce intensities as high as 10¹⁴ W/cm² and advanced laser facilities scale to the 10¹⁶ W/cm² and even to the 10¹⁸ W/cm² at low repetition rate, opening the path for laser systems to drive secondary sources of X-ray radiation, ultrafast electrons and even the prospect of tabletop laser driven particle colliders.

In this progress toward laser driven secondary sources, mid-IR lasers are of particular interest as their inherent long wavelength allows for ponderomotive scaling of light matter interactions. In particular, the generation of coherent soft X-ray radiation via high harmonic generation (HHG) – in demand for applications such as spintronic or metrology in industrial semi-conductor manufacturing with high societal impact – hinges upon the development of reliable mid-IR lasers with intensities in the 10¹⁴-10¹⁵ W/cm² range and average powers in the 10-100 W regime.

In this talk, I will present an overview of our team’s effort in the development of long wavelength lasers specifically tailored to drive secondary sources of soft X-ray radiation via HHG as well as first applications in metrology at 6.7 nm. Specifically, I will present our mJ-class, kHz, 3 mm wavelength optical parametric chirped pulse amplifiers and their HHG beam line, our high average power, MHz repetition rate, 1.5 mm optical parametric amplifier and our efforts investigating broadband Ho³⁺-doped gain media to efficiently drive high harmonics generation into the water window (280-550 eV).

BIO:

Michaël graduated with a Masters degree in engineering from the Ecole Nationale Supérieure de Physique de Marseille (France). He graduated with a PhD in Optics in 2011 from the University of Central Florida working on the development of ultrafast nonlinear amplifiers for high field physics applications. He then was a post-doctoral associate and later a research fellow at the Institute of Photonic Sciences (ICFO) in Barcelona, Spain. There he worked on the development of long wavelength, ultrafast lasers. These lasers have been used for high harmonic generation into the soft X-ray region and for ultrafast electron diffraction experiments. He then moved to the Deutsches Elektronen Synchrotron (DESY), in Hamburg, Germany as a researcher and worked on the development of laser driven electron gun and electron accelerators with the ultimate goal of providing an all-laser driven hard X-ray source. He joined the KM group at JILA in the summer of 2018 and has since then been working on developing a mid-IR laser facility to drive high harmonics into the soft X-ray with stability compatible with challenging experiments. In 2019, Michaël was awarded the OSA Outstanding Reviewer Award. He is also a Topical Editor for Optics Letters, covering the fields of ultrafast and nonlinear optics.