From Theory to Reality: Progress and Challenges in Free-Electron Laser Development

Dear Colleagues,

Over recent years, developing and applying ultrashort coherent radiation pulses has made tremendous progress. The advent of ultrashort light sources and attosecond metrology has greatly advanced the understanding of electron motion in atoms and molecules. Ultrafast electron motion can be encountered in many quantum systems. Therefore, the application of ultrashort radiation pulses encompasses a broad range of fields, extending from chemical sciences to condensed matter physics. Recently, free-electron lasers (FELs), generating ultrashort pulses with high peak power from the extreme ultraviolet region to the hard X-ray region, are opening a multitude of new scientific opportunities towards the exploration of molecular and atomic structures in the areas of applied physics, chemistry, biology, material science, etc., where employing the coherent powerful ultrashort pulse in the short wavelength range is essential. In this respect, this Special Issue invites manuscripts that theoretically and experimentally address the current challenges in these domains. All theoretical, numerical, and experimental papers are accepted. Topics include, but are not limited to, the following:

• Ultrashort free-electron laser pulse generation.
• Enhanced self-amplified spontaneous emission (ESASE) free-electron laser.
• Generation of coherent free-electron laser radiation.
• Hard X-ray and soft X-ray self-seeding free-electron laser.
• Echo-enabled and high-gain harmonic generation free-electron laser (EEHG and HGHG).
• Characterization of free-electron laser pulses.

Dr. Najmeh Mirian
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Photonics is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

• free-electron laser
• ultrashort pulse
• hard X-ray FEL
• soft X-ray
• seeded FEL
• seeding FEL
• EEHG
• HGHG
• ESASE
• SASE