Author: Gillespie, W.A.
Paper Title Page
TUPC41 A Femtosecond Resolution Electro-Optic Diagnostic Using a Nanosecond-Pulse Laser 474
  • S.P. Jamison
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • W.A. Gillespie, D.A. Walsh
    University of Dundee, Nethergate, Dundee, Scotland, United Kingdom
  Funding: We gratefully acknowledge support under CERN collaboration agreement KE1865/TE
Electro-optic longitudinal profile diagnostic systems with intrinsically improved reliability and a time resolution of 20 fs rms are being developed for CLIC. Exploiting the electro-optic effect, the bunch electric field 'pulse carves' an optical replica from a narrow bandwidth nanosecond duration laser probe. All-optical characterisation of the optical replica is via spectrally resolved auto-correlation, providing a sub-20fs resolution capability. An optical parametric amplification stage following the pulse carving, and driven by same nanosecond laser that provides the probe, enables sufficient intensity for single-shot measurement. In basing the optical system on nanosecond Q-switched lasers, bypassing complex femtosecond laser systems, the potential for robust instrumentation development is enhanced. The bandwidth limitations of the electro-optic materials are being addressed through investigations into multiple crystal detectors, and THz induced second harmonic generation on metal surfaces. Experimental results on the optical subsystems, using laser-produced THz as an electron bunch mimic, are presented together with performance projections for the integrated system.