Plasma mirror focal spot quality for glass and aluminum mirrors for laser pulses up to 20 ps
| Autor: | P. Forestier-Colleoni, Alexander M. Rubenchik, Tammy Ma, Jaebum Park, Farhat Beg, Brandon Edghill |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Materials science
business.industry Pulse duration Order (ring theory) Curved mirror 02 engineering and technology 021001 nanoscience & nanotechnology Laser 01 natural sciences Atomic and Molecular Physics and Optics law.invention 010309 optics Optics law 0103 physical sciences Focal Spot Size 0210 nano-technology National Ignition Facility business Inertial confinement fusion Intensity (heat transfer) |
| Zdroj: | Optics letters. 45(5) |
| ISSN: | 1539-4794 |
| Popis: | High-intensity short-pulse lasers are being pushed further as applications continue to demand higher laser intensities. Uses such as radiography and laser-driven particle acceleration require these higher intensities to produce the necessary x-ray and particle fluxes. Achieving these intensities, however, is limited by the damage threshold of costly optics and the complexity of target chambers. This is evidenced by the Advanced Radiographic Capability (ARC) short-pulse laser at the National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory, producing four high-energy ≈ 1 k J laser pulses at 30 ps pulse duration, being limited to an intensity of 10 18 W / c m 2 by the large focal spot size of ≈ 100 µ m . Due to the setup complexity of NIF, changing the location of the final focusing parabola in order to improve the focal spot size is not an option. This leads to the possible use of disposable ellipsoidal plasma mirrors (PMs) placed within the chamber, close to the target in an attempt to refocus the four ARC beams. However, the behavior of PMs at these relatively long pulse durations (tens of picoseconds) is not well characterized. The results from the COMET laser at the Jupiter Laser Facility carried out at 0.5 to 20 ps pulse durations on flat mirrors are presented as a necessary first step towards focusing curved mirrors. The findings show defocusing at longer pulse durations and higher intensities, with less degradation when using aluminum coated mirrors. |
| Databáze: | OpenAIRE |
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