Research

I did my PhD in attosecond science with a focus on high harmonics generation (HHG) from solids. For my postdoc I took a different route and I am excited to work on projects merging my expertise with ultrafast lasers and nonlinear optics with a new avenue for me of quantum optics. I work on experimental implementation of strong-field nonlinear experiments with a non-classical bright-squeezed vacuum source.

During my PhD I worked on a wide range of attosecond science with a main focus on HHG spectroscopy within wide-band dielectrics. In particular, I looked into the strong field effects near the edge of a band structure. I also collaborated on pump-probe high harmonic spectroscopy of aerosols and XFEL experiments with liquid jets.

Throughout my career, I’ve amassed extensive hands-on experience in laser labs. However, I’ve also dedicated myself to streamlining and enhancing my experiments through the development of an open-source optical lab interface package. Furthermore, my involvement with XFEL and HHG beamlines has equipped me with a proficiency in extensive data analysis and the implementation of machine learning techniques.

Main Projects

• Postdoctoral Fellow at JASLab, NRC, Canada working on Attosecond Quantum Optics projects
• Co-Investigator and Target Area Operator at CLF Artemis Beamtime “Investigating the wavelength dependence of High Harmonic Generation in solids”
• Investigator on Pump-Probe HHG in aerosols project in collaboration with ETH Zurich

Publications and Conferences

• Purschke, David, Kowalczyk, Katarzyna M., et al. “Statistics of spontaneous photocurrent in LT-GaAs Electrodes driven by bright-squeezed vacuum.” 2025 Photonics North
• Cavaletto, Stefano M., Kowalczyk, Katarzyna M., et al. “The attoscience of strong-field-driven solids.” Nature Reviews Physics (2024): 1-12.
• Allegre, Hortense, et al. “Extension of high-harmonic generation cutoff in solids to 50 eV using MgO.” Optics Letters 50.5 (2025): 1492-1495.
• Barnard, Jonathan CT, et al. “Delivery of stable ultra-thin liquid sheets in vacuum for biochemical spectroscopy.” Frontiers in Molecular Biosciences 9 (2022): 1044610.
• Kowalczyk, Katarzyna M., et al. “Complex Structures of Spatially and Spectrally resolved Solid High Harmonics.” 2023 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC). IEEE, 2023.
• Kowalczyk, Katarzyna M., et al. “Ultrafast Processes Optimisation for Wideband Dialectrics.” JSAP-Optica Joint Symposia. Optica Publishing Group, 2022.
• Wyatt, Adam S., Kowalczyk, Katarzyna M., et al. “Spatially-and Spectrally-Resolved Structures in High Harmonic Generation from Solids.” Ultrafast Optics. Optica Publishing Group, 2023.
• Allegre, Hortense, et al. “Anisotropic High Harmonic Generation in Wide Bandgap Dielectrics.” The European Conference on Lasers and Electro-Optics. Optica Publishing Group, 2023.
• Kowalczyk, Katarzyna M., and Matthews Mary, “Chirp dependence of EUV generation in MgO using few cycle mid-IR pulses.” High Intensity Lasers and High Field Phenomena. Optica Publishing Group, 2022.