Abstract :
Single-shot measurement of the relative delay between x-ray free
electron laser (FEL) pulses and optical laser pulses has now been
improved to 10 fs rms error and has successfully been demonstrated
for both soft and hard x-ray pulses (500 - 9600 eV). It is based on
x-ray induced step-like reduction in optical transmissivity of a
semiconductor membrane (Si3N4). The transmissivity is probed by an
optical continuum spanning 450 - 650 nm where spectral chirp provides
a mapping of the step in spectrum to the arrival time of the x-ray
pulse relative to the optical laser system. Various other materials
are also investigated demonstrating a unique optical modulation for
each.
Affiliation :
The Linac Coherent Light Source, SLAC National Accelerator Laboratory,
Menlo Park, CA, USA