OSE Dissertation Defense by Mr. Ali Rastegari on Filaments and their application to air lasing, spectroscopy, and guided discharge

Departmental News

Ali Rastegari 225x300

Posted: May 22, 2023

Date, Time and Location:

Friday, May 26, 2023, from 1:00 PM -2:30 PM at CHTM, Room 103


Laser filamentation is a fascinating phenomenon that occurs when an intense laser beam travels through transparent materials, in particular air. At sufficiently high power (TW in the near IR, GW in the UV), instead of spreading out like a regular laser beam, something remarkable happens: the laser beam becomes tightly focused, creating a thin and intense column of light called a laser filament. Laser filamentation is characterized by two main properties: (I) a high-intensity core that remains narrow over long distances beyond the Rayleigh range and (II) a low-density plasma channel within the core. In recent years, laser filamentation has gained significant attention due to its unique properties and wide range of applications.

This talk will provide an introduction to laser filamentation and discuss beam profile measurements related to UV filaments. Additionally, the results of experiments involving the applications of laser filaments will be presented. It has been demonstrated that UV filaments can be utilized for laser breakdown spectroscopy, leading to higher resolution and accuracy. Furthermore, the phenomenon of air lasing induced by both UV and IR laser filaments was investigated. Finally, the potential application of UV filaments for guiding and triggering electrical discharges is studied.


Ali obtained his Bachelor of Science in physics from the University of Tehran. Later, he also obtained his Master of Science in atomic and molecular physics from the same university. During his Master's degree, he worked on the design and development of two Transversely Excited (TE) CO2 lasers, in which a new pre-ionization technique was introduced. Since beginning his PhD at UNM, Ali has been a member of Dr. Diels' research group working on laser filamentation and its applications. He also received his Master of Science in Optical Science and Engineering (OSE) form University of New Mexico.