The Ohio State University

Ultrafast laser materials interaction: Intro

The invention of Chirped Pulse Amplification (CPA) by Mourou and Strickland (2018 Nobel Prize in Physics) allowed the rapid development of high power ultrafast lasers that is opening up novel pathways in Material Science and Engineering. high intensity lasers are used as the finest ‘scalpels’ of the universe to perform eye and other surgeries 1,2, surface engineering 3,4 (e.g. super-hydrophobic surfaces) and machining 5 not possible before. At the heart of many of these phenomena is the femtosecond laser induced damage (fs-LID) of solids, during which, a strong, non- perturbative optical field near–instantaneously6 creates a high density of carriers (plasma) via electron transition from valence to conduction band (multiphoton to tunneling process, VB → CB), accelerates the carriers non-thermally, which, eventually thermalize within themselves and imparts energy to the lattice. Depending on how much energy density is transferred to the lattice in a pulse, the solid may exhibit rapid phase change and experience ablation, liquefaction, amorphization and disorder with corresponding change in surface morphology (damage but not ablation), or undergo changes to subtle to observe by traditional means (optical or electron microscopy of surface), but extremely important for understanding of multi-pulse effects. Although experimental, theoretical and computational efforts on this topic have been ongoing for over two decades, most of them were not coordinated to tackle   a   fundamental non-perturbative phenomenon whose temporal regime extends     from     attoseconds (ionization/transition) to nanoseconds (material removal) and beyond 7. Thus, significant gaps in fundamental understanding remain to this day. My lab investigates these processes by using dynamic and non-dynamic techniques, varying laser pulse durations (few to many cycles of optical oscillations) and wavelengths (near to mid-IR).

Major Thrusts:

    • Strong laser fields modify materials and material systems 8–10
    • Material and material systems alter strong laser fields. 11–13

References:

  1. Latz, C., Asshauer, T., Rathjen, C. & Mirshahi, A. Femtosecond-laser assisted surgery of the eye: Overview and impact of the low-energy concept. Micromachines 12, 1–21 (2021).
  2. Chung, S. H. & Mazur, E. Surgical applications of femtosecond lasers. J. Biophotonics 2, 557–572 (2009).
  3. Vorobyev, A. Y. & Guo, C. Colorizing metals with femtosecond laser pulses. Appl. Phys. Lett. 92, 041914 (2008).
  4. Feng, X. & Jiang, L. Design and creation of superwetting/antiwetting surfaces. Adv. Mater. 18, 3063–3078 (2006).
  5. Malinauskas, M. et al. Ultrafast laser processing of materials: from science to industry. Light Sci. Appl. 5, e16133 (2016).
  6. D. Hui, H. Alqattan, S. Zhang, V. Pervak, E. Chowdhury, and M. T. Hassan, “Ultrafast optical switching and data encoding on synthesized light fields,” Sci. Adv. 9(8), eadf1015 (2023). Cover of February 24, 2023 issue.
  7. Sundaram, S. K. & Mazur, E. Inducing and probing non-thermal transitions in semiconductors using femtosecond laser pulses. Nat. Mater. 1, 217–224 (2002).
  8. Kafka, K. R. P. et al. Time-resolved measurement of single pulse femtosecond laser-induced periodic surface structure formation induced by a pre-fabricated surface groove. Opt. Express 23, (2015).
  9. Talisa, N. & Chowdhury, E. A. Few cycle pulse laser ablation study of single layer TiO2 thin films using time resolved surface microscopy. Opt. Express 26, 30371–30382 (2018).
  10. Talisa, N. et al. Comparison of damage and ablation dynamics of thin film interference coatings initiated by few cycle pulses vs longer femtosecond pulses. Opt. Lett. 45, 2672 (2020).
  11. Werner, K. et al. Ultrafast mid-infrared high harmonic and supercontinuum generation with n2 characterization in zinc selenide. Opt. Express 27, 2867 (2019).
  12. Shcherbakov, M. R. et al. Photon acceleration and tunable broadband harmonics generation in nonlinear time-dependent metasurfaces. Nat. Commun. 10, 1345 (2019).
  13. Shcherbakov, M. R. et al. Generation of even and odd high harmonics in resonant metasurfaces using single and multiple ultra-intense laser pulses. Nat. Commun. 12, 4185 (2021).