Tutorial reflects on making mirrors for petawatt lasers

High energy, short pulse petawatt laser systems have applications in science, engineering, and industry, such as in high energy density science and other research using laser-based accelerators. Mirrors – an important component of petawatt laser systems, are often a source of system failure. Laurence et al. publish a tutorial for researchers unfamiliar with the technology, and provide guidelines on the design, fabrication, and testing of mirrors for petawatt lasers.

“This is a good chance to take a look at the overall field from a technological and scientific perspective,” said author Ted Laurence.

For a mirror to be used in a petawatt laser system, it needs to meet the reflection and dispersion requirements while being durable enough to withstand the intense light generated by the petawatt laser.

The authors explain the designing requirements for petawatt mirrors and methods for assessing laser-induced damage. They present a summary on the understanding of the damaging process in the mirror layers, and discuss solutions, such as possible improvements in the mirror coating process for reducing light-modifying flaws – a feature that damages mirror layers by unintentionally enhancing the laser intensity.

The tutorial outlines potential directions of the field that may increase petawatt laser performance, such as the development of mirrors capable of handling high repetition rates, while emphasizing the need for integrated management and design of mirrors for petawatt lasers.

“In particular, optical design and fabrication must be combined with rigorous laser-induced damage testing of mirror designs, monitoring of optical components in laser systems, and a scientific understanding of fundamental design and damage limitations to successfully field mirrors for petawatt lasers,” Laurence said.

Source: “Mirrors for petawatt lasers: Design principles, limitations, solutions,” by T. A. Laurence, D. A. Alessi, E. Feigenbaum, R. A. Negres, S. R. Qiu, C. W. Siders, T. M. Spinka, and C. J. Stolz, Journal of Applied Physics (2020). The article can be accessed at https://doi.org/10.1063/1.5131174 .