Optimisation of X-ray harmonic generation in capillaries by pulse shaping using an acousto-optic programmable filter

This study presents an acousto-optic programmable filter (AOPDF) that provides rapid, highly specific shaping of 0.3 laser pulses, which is used to change both the intensities and positions of generated X-ray harmonic orders. Because of the simple and accurate adjustment of spectral phase offered by AOPDF, this ability to modify and shift the X-ray spectrum can be used to produce frequency-agile X-ray tunable sources, as well as providing improved insight into the generation process in capillaries in which the key phase matching is modified by processes which depend on pulse shape.