Prof Peter Norreys FInstP;

Abstract:

We present measurements of the spatial and temporal coherence lengths of the 4th harmonic of a 1053 nm, 2.5 ps laser generated during high intensity (up to 10(19) wcm(-2)) interactions with a solid target. Coherence lengths were measured by use of a Young's double slit interferometer. The effective source size, as defined by the Van Cittert-Zernicke theorem, was found to be 10 similar to 12 mu m, and the coherence time was observed to be in the range 0.02 similar to 0.4 ps.

Abstract:

VULCAN is a multi-beam, multi-terawatt laser facility based on Nd:glass operating at 1053 nm. The system is highly versatile, supplying four experimental areas with laser radiation at a range of pulse durations from 700 fs to 20 ns, at fundamental frequency, frequency doubled, or, as a limited option, frequency tripled wavelengths. Beams are available in a number of geometries dictated by the university based programs, which at present include: cluster; line focus including x-ray laser oscillator/amplifier geometry; backlighting; probing; and chirped pulse amplification (CPA) configurations. The system has eight beams which can deliver synchronized long and short pulses including two beams which can deliver subpicosecond CPA pulses. The CPA capabilities on VULCAN are an integral part of the laser system, not only delivering sub-picosecond pulses, but allowing uncompressed pulses and multi-pulses to be delivered to the target areas synchronized with the nanosecond pulses. This paper describes the system configuration, details the means of pulse synchronization and presents some of the pulse manipulation techniques used on VULCAN to provide the laser requirements for the experimental program.