Spatial and temporal coherence measurements of harmonics of a 1053 nm, 2.5 ps laser interacting with solid surfaces

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 10¹⁹ 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-Zemicke theorem, was found to be 10 ~ 12μm, and the coherence time was observed to be in the range 0.02 ~ 0.4 ps.