The drive for shorter pulses for use in techniques such as high harmonic generation and laser wakefield acceleration requires continual improvement in post-laser pulse compression techniques. The two most commonly used methods of pulse compression for high intensity pulses are hollow capillary compression via self-phase modulation (SPM)  and the more recently developed filamentation . Both of these methods can require propagation distances of 1-3 m to achieve spectral broadening and compression. Additionally, hollow capillary compression requires post compression of the broadened pulse by chirped mirrors. Filamentation trades the efficiency of hollow capillary compression (67%) for ionisation-induced pulse self-compression. A mixture of SPM and plasma generation increases the spectral bandwidth of the pulse; however this occurs only in a small region at the centre of the beam. Spatial filtering is required to achieve the shortest pulses, reducing the efficiency to 20%. Although the majority of hollow core capillary compression requires long propagation distances, compression in short capillaries  with significant plasma generation has been demonstrated to be a promising technique.
© 2011 Optical Society of AmericaPDF Article