Unifying laser and accelerator physics is essential for the development of future accelerators, light sources, and other scientific instruments due to increasingly synergistic advances at the cross section between these two fields. Laser fields are ideal agents to tailor the 6-D phase-space distribution of charged particle beams because they can imprint correlations with extremely high spatio-temporal precision.

In addition to long-standing uses in photo-injectors and compact acceleration, recent laser applications to free electron laser seeding, accelerators on a chip, hybrid x-ray light sources, and more have highlighted the need for further research into laser-particle interactions.

This Research Topic is intended to compile various research topic areas that fill the breach between laser and accelerator physics, and to highlight the challenges that this interdisciplinary field faces to expose present and future opportunities in laser research and development to serve accelerator technology and applications, from instrumentation requirements to science cases. The scope of this issue includes some of the following topical areas:

• Novel ultrafast laser driver concepts and instrumentation
• Laser-based attosecond electron sources for ultrafast electron diffraction and imaging
• Laser wakefield acceleration of electrons and positrons for high-energy physics
• Linear and Nonlinear laser-particle interactions
• Novel 6D phase-space charged-particle manipulation concepts and applications
• Laser-based secondary emission x-ray and gamma ray sources and applications
• Hybrid (RF, THz, optical) electron and secondary emission sources
• Novel free-electron laser concepts and instrumentation
• Attosecond timing and synchronization systems

Keywords: Ultrafast lasers, relativistic laser-matter interactions, accelerator physics, Free-electron lasers

Important Note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.