Thumbnail
Access Restriction
Open

Author Montgomery, D. S. ♦ Johnson, R. P.
Sponsorship (US)
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Publisher The American Physical Society
Language English
Subject Keyword PLASMA PHYSICS AND FUSION TECHNOLOGY ♦ BACKSCATTERING ♦ DESIGN ♦ FIBERS ♦ LIGHT SOURCES ♦ OPTICAL FIBERS ♦ PHYSICS ♦ RESOLUTION ♦ SPECTROMETERS ♦ SPECTROSCOPY ♦ US NATIONAL IGNITION FACILITY ♦ WAVELENGTHS
Abstract Optical fibers are used to couple light into fast time-resolved spectrometers for many applications. Here several issues arise that can seriously limit the temporal resolution, such as the wavelength dependent group delay, and intermodal dispersion. These issues are investigated in 10 m length fibers using either a 400 {mu}m core step index or graded index fiber. A unique broadband (400--700 nm) short pulse ({approx}1 ps) light source is used to measure the fiber group delay with a time-resolved spectrometer. Intermodal dispersion is also studied in these fibers using a narrow-band 1 ps pulse that is injected into the fiber with various coupling schemes, and a novel technique is employed to record the time-dependent angular mode structure. Finally, a conceptual design using {approx}100 {mu}m core graded-index fibers is proposed for multichannel streaked optical spectroscopy on the National Ignition Facility. Designs appropriate for a low spectral resolution instrument (stimulated Raman backscattering) and a high spectral resolution instrument (stimulated Brillouin backscattering) are presented. The fiber dispersion issues are discussed in the design of these diagnostics.
ISSN 00346748
Educational Use Research
Learning Resource Type Article
Publisher Date 2001-01-01
Publisher Place United States
Journal Review of Scientific Instruments
Volume Number 72
Issue Number 1


Open content in new tab

   Open content in new tab