Colorado State University (Generation and Atmospheric Propagation of High Energy Ultrashort Laser Pulses at High Repetition Rates)
Abstract
Defense applications in directed energy, such as channeling of intense laser and microwave beams and guiding of electoral discharges in the atmosphere, x-ray and gamma ray generation, remote sensing, and others will greatly benefit from the availability of efficient high energy ultrashort pulse lasers capable of delivering multi-Joule-level pulses at kHz repetition rates (kW average powers). Presently, Joule-level picosecond and femtosecond lasers are mostly limited to repetition rates of 10 Hz. Moreover, since they are typically pumped by flashlamps, these lasers are large in size, inefficient, and nonportable. Tests of Joule-level energy laser pulse propagation in the atmosphere have been consequently limited to low repetition rates. We have recently demonstrated a new high average power, high energy, picosecond diode-pumped Yb:YAG lasertechnology (achieving for example 5 ps, 1.5 J at 500 Hz: 750 W average power, Optics Letters, 41, 3339 (2016)), that is scalable to multi-kW average power. Here we propose to use 1 J picosecond laser pulses generated at 1 kHz by this technology, to study the laser induced damage threshold on dielectric multilayer coatings, and the propagation of kW average power beams of high energy ultrashort laser pulses in the atmosphere. We also propose to work towards extending the high energy kHz repetition rate laser capability to the femtosecond range by using this laser technology to pump a high average power Ti:Sapphire laser testbed that will produce 0.25 J pulses of 25 fs duration at 1 kHz repetition rate. This laser, that is also beyond the state-of-the-art, will allow similar beam propagation and materials damage tests at high repetition rates with highenergy femtosecond pulses to be performed. This project will also contribute to directed energy by providing novel concepts in the engineering of interference coatings (ICs) for high energy laser systems to realize superior performance in terms of robustness to laser damage under high average power and high peak power loading conditions. In addition, the project will train students in thegeneration, propagation, and utilization and intense high average power lasers.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Apr 25, 2019
- Source ID
- N000141912254
Entities
People
- Jorge G. Rocca
Organizations
- Colorado State University
- Office of Naval Research
- United States Navy