Dr. Kyle Kafka, who recently obtained his PhD from Chowdhury group in 2017, accepted a Research Associate position at the prestigious Laboratory for Laser Energetics (LLE), Rochester, USA. LLE, home of the OMEGA and OMEGA EP laser facilities, is a National Nuclear Security Administration (NNSA-DOE) supported laboratory, and is known as one of the top high energy density physics (HEDP), and Ultra-intense laser physics and technology laboratories in the world. Dr. Kafka will closely work with the Optical Materials Technology and Laser Technology groups, helping develop next generation lasers like MTW OPAL (Multi-TeraWatt Optical Parametric Amplifier Laser system) and one hundred petawatt EP-OPAL.
The oral presentation of Kyle R. P. Kafka from Chowdhury Group titled, “Few-cycle pulse laser-induced damage of thin films in air and vacuum ambience” has been selected as the best oral presentation at the 48th Boulder Laser Damage Symposium (https://spie.org/conferences-and-exhibitions/laser-damage). For more info, follow link: http://physics.osu.edu/news/graduate-student-kyle-kafka-wins-best-oral-presentation-award-spie-laser-damage-2016
Femtosecond Solid Dynamics Lab of Prof. Chowdhury has participated in the world-wide Thin Film Laser damage competition at the 48th Boulder Laser Damage Symposium (world’s longest running laser conference) as the official Damage Testing Facility for 2015 and 2016. They worked with the Laser Damage group at Lawrence Livermore National Laboratory to set the protocol and analysis for testing the most advanced high damage threshold broad-band dielectric reflective coatings for high power laser applications available in the world, to be used in next generation billion dollar laser facilities like the European Extreme Light Infrastructure, or ELI ( three facilities: www.eli-beams.eu, www.eli-hu.hu, www.eli–np.ro) pushing physics frontiers of nonlinear QED, atto-second science and nuclear physics. This year, 19 different companies/research facilities from three continents sent 42 of their most advanced samples to be tested in the competition. The result and winning ultra-fast high reflector of the competition was announced at the Boulder Damage Symposium last week (25th-28th September, 2016). More information about this work can be found in https://spie.org/conferences-and-exhibitions/laser-damage and http://spie.org/Publications/Proceedings/Paper/10.1117/12.2195592.
This work was partially supported by the Air Force Office of Scientific Research.
Fig. PI-chart of the breakdown of the Laser Damage Competition participants by country around the world
Prof. Chowdhury, in collaboration with Prof. Jay Gupta, won one of the three of this year’s Institute of Material Research (IMR) team building seed grant awards, to study intense field interaction of single atomic defect states on solid surfaces with atomic spatial and femtosecond temporal resolution with the help of a Scanning Tunneling Microscope (STM) coupled to a portable femtosecond laser. More information on IMR seed program is found here.
Prof. Chowdhury’s Lab is part of AFOSR MURI (Multi-disciplinary Univeristy Research Initiative) program headed by Prof. Dimauro of OSU Physics. The Program focuses on probing intense field light matter interaction in Mid-IR frequencies. Femto-solid lab will primarily study how femtosecond pulses in Mid-IR wavelengths causes damage to solids. For more information, please follow the link.
(Left) LLNL $45 million HAPLS laser developed for ELI Beamline, > 1PW, 30 fs, 10 Hz.
(Right) Artist rendition of ELI beamline in Czec Republic, EU 350 million facility being constructed
- Chowdhury Lab was contracted recently by LLNL to perform broad band laser damage testing for the mirrors for this laser
- The test has been completed in 2014, and based on the test results, vendors for HAPLS mirrors will be chosen
- Strong interest in future ultra-broad band vacuum Laser Damage Threshold for the same project, new contract under way
Undergrad Evan Lang (Adviser: Enam Chowdhury) worked at the Air Force Research Laboratory for Directed Energy in Kirtland Air Force Base in Summer 2014 as an AFRL fellow (http://afrlscholars.usra.edu/). For his outstanding contribution to the Project, he received the Outstanding Scholar Award for undergraduate fellows in Directed Energy at the end of his term there.
Last week, he presented his work at the Directed Energy Ultra Short Pulse workshop 2014 at Boulder, CO.
He describes his research below:
Our efforts are directed towards fundamental understanding of intense laser matter interaction near material damage threshold. Although laser interaction with solids began with the advent of the laser 50+ years ago, many important aspects of the interaction, especially those that involve femtosecond (FS) lasers, are not clearly understood. Femtosecond laser interacts with matter differently than continuous wave (CW) lasers or pulsed nano-second (NS) lasers do. Intense CW and NS lasers in most cases, cause the interacting matter to heat up rapidly, melt and ablate. However, intense FS lasers cause the electrons in solid to rapidly ionize/transit to conduction band (dielectrics) and the electrons in the conduction band (metallic) are then accelerated by the laser field. These non-thermal distribution of electrons then causes rapid changes to the material surface before thermalization with lattice is achieved.
Many Applications required the use solids interacting with multiple femtosecond pulses at different repetition rates, between which the material may evolve for nano-seconds to micro-second time scales before the next pulse comes in. Understanding these phenomena require probing the evolution of interaction from femtosecond to microsecond time scale, over nine orders of magnitude in time!
This laboratory is supported by