H. Schlarb, S. Düsterer, J. Feldhaus, J. Hauschildt, R. Ischebeck, K.
Ludwig, B. Schmidt, P. Schmüser, S. Simrock, B. Steffen, F. Van den Berghe,
A. Winter
DESY, Hamburg
P.H. Bucksbaum, A. Cavalieri, D. Fritz, S. Lee, D. Reis
Michigan University, Ann Arbor, Michigan
For pump-probe experiments at the VUV-Free Electron Laser at DESY, an external
optical laser system will be installed, capable of delivering ultra-short pulses
of high intensity. The laser pulses with a center wavelength of 800 nm are synchronized
with the VUV-FEL beam which covers the wavelength range between 6 nm and 80
nm. The expected pulse durations are typically 100 fs FWHM or below. For high-resolution
pump-probe experiments a precise knowledge of the time difference between both
pulses is mandatory. In this paper we describe the layout and the design of
a high-precision electron bunch arrival time monitor based on an electro-optic
technique. We present the numerical results of simulations that include: the
laser propagation in a specifically designed demanding optical system, the laser
transport through a 150 m long optical fibre, the electro-optically induced
effect in different types of crystals and for different electron bunch shapes
as well as the effects of wake fields on the co-propagating electric-fields
and their impact on the observable signals.