Increased damage thresholds due to laser pulse modulation Metadata

Title

• Main Title Increased damage thresholds due to laser pulse modulation

Creator

• Author: Feit, M. D.
  Creator Type: Personal
  Creator Info: Lawrence Livermore National Lab., Livermore, CA (United States)
• Author: Musher, S. L.
  Creator Type: Personal
• Author: Shapiro, E. G.
  Creator Type: Personal
  Creator Info: Inst. of Automation and Electrometry, Novosibirsk (Russian Federation)
• Author: Rubenchik, A. M.
  Creator Type: Personal
  Creator Info: Inst. of Automation and Electrometry, Novosibirsk (Russian Federation)

Contributor

• Sponsor: United States. Department of Energy.
  Contributor Type: Organization
  Contributor Info: USDOE, Washington, DC (United States)

Publisher

• Name: Lawrence Livermore National Laboratory
  Place of Publication: California
  Additional Info: Lawrence Livermore National Lab., CA (United States)

Date

• Creation: 1995-05-30

Language

• English

Description

• Content Description: Nonlinear self-focusing in laser glass imposes limits on the energy fluence that can be safely transmitted without risking damage. For this reason, it is desirable to strictly limit the peak to average spatial variations of fluence by smoothing schemes such as Smoothing by Spectral Dispersion (SSD). While spatial variations are problematic, the same is not necessarily true of temporal variations since normal group velocity dispersion tends to smooth out temporal peaks caused by spatial self-focusing. Earlier work indicated that increased bandwidth can delay the onset of self focusing. The present work re-examines the question of self focusing threshold increases due to high bandwidth by investigating another source of such increase in three dimensional beam breakup--the bending instability. For simplicity, the authors consider the behavior of a single space-time speckle. Normal dispersion can lead to splitting of the pulse and delay of self focusing for short enough pulses as noted above. In addition to the self focusing instability, the laser beam is also subject to the so-called bending (sausage like) instability which can spatially disperse the field maxima over time. Because the bending instability breaks an initial axial symmetry, a full three dimensional numerical simulation is required to study it accurately. Such calculations are possible, but costly. The authors have used a modified 2D nonlinear Schroedinger equation with a high power nonlinearity since this mimics the 3D behavior of the competition between self focusing and bending. This study is relevant for inertial confinement conditions.
• Physical Description: 8 p.

Subject

• Keyword: Radiation Flux
• Keyword: Two-Dimensional Calculations
• Keyword: Beam Optics
• STI Subject Categories: 70 Plasma Physics And Fusion
• Keyword: Laser Radiation
• Keyword: Theoretical Data
• Keyword: Instability
• Keyword: Modulation
• Keyword: Energy Transfer
• Keyword: Nonlinear Problems
• Keyword: Focusing
• Keyword: Dispersion Relations
• Keyword: Laser Materials
• Keyword: Inertial Confinement

Source

• Conference: 1. annual solid-state lasers for application to inertial confinement fusion meeting, Monterey, CA (United States), 30 May - 2 Jun 1995

Collection

• Name: Office of Scientific & Technical Information Technical Reports
  Code: OSTI

Institution

• Name: UNT Libraries Government Documents Department
  Code: UNTGD

Resource Type

• Report

Format

• Text

Identifier

• Other: DE95016607
• Report No.: UCRL-JC--121285
• Report No.: CONF-9505264--5
• Grant Number: W-7405-ENG-48
• DOI: 10.2172/102207
• Office of Scientific & Technical Information Report Number: 102207
• Archival Resource Key: ark:/67531/metadc625805

Note

• Display Note: INIS; OSTI as DE95016607