Femtosecond laser induced damage in extremes: from single cycle to atomic resolution
Abstract
We will study laser damage from extremely bright, short time duration laser pulses. We will measure how materials behave on time scales as short as 1 femtosecond (1/1000 of a trillionth of a second) and on spatial scales as small as that of an atom. Laser damage can be highly controlled when ultra-short time duration laser pulses are used and has had a large impact on society by advancing material preparation and measurement, manufacturing, and surgery. This project is a fundamental study using state-of-the-art experimental techniques to test the validity and limit of current theoretical and computational modeling frameworks and to extend our knowledge and understanding near the material damage threshold. We will study laser damage using pulses that are only a few optical cycles in duration (“few cycle pulses”, FCP or even shorter “near-single-cycle-pulse”, NSCP), the evolution of damage under multiple pulse excitation, and the dynamics of laser driven ablation over a range of wavelengths and materials and using light with orbital angular momentum where the laser polarization varies about the laser beam in a systematic fashion. We will use a combined experimental, theoretical, and computational approach to explore the breakdown of existing models and theory when FCP are used including the ionization process which initiates laser damage, time-resolved atomic scale behavior using a custom approach employing a scanning tunneling microscope (STM), the buildup of defects during multipulse excitation using an STM, and custom short pulse, ultraintense lasers and wavelength conversion apparatus. State-of-the-art high performance computing will be used including new algorithms developed by us to predict and explain the experimental results. The result of this work will be a better, more fundamental understanding of how damage occurs and how to control it. New opportunities for useful forms of laser damage that can improve current applications will be identified.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 12, 2021
- Source ID
- FA95502010278
Entities
People
- Enam Chowdhury
Organizations
- Air Force Office of Scientific Research
- Ohio State University
- United States Air Force