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I am reading about shock waves and their origin. During my study i have found that the long pulse lasers (nanosecond-miliseconds duration) are used to generate the shock waves in the materials, whereas I have found a little mention about the use of ultrashort pulses (duration < 1 picoseonds) for the generation of shock wave.

ultrashort pulses have larger intensity and can generate faster impulses, why shock waves could not be generated by such pulses

Thanks in advance

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    $\begingroup$ (1) you only need so fast of a pulse to do what you need to do. (2) Dumping more energy in to the material in a shorter time can lead to worse coupling as the material decides to vaporize (and disrupt further coupling). $\endgroup$
    – Jon Custer
    May 5, 2016 at 19:13

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Ultrafast lasers do induce shock waves; for example, see: Ultrashort shock waves in nickel induced by femtosecond laser pulses.

In many ultrafast experiments an effort is made to minimize these shock waves. While doing ultrafast photo-electron diffraction experiments I had to change the method of preparation of the samples so that they didn't fall apart after a few million excitation pulses. Since the materials had to be ultrathin, 10-20 nm thick, in order to support the photo-electron diffraction requirements, this limited the choice of materials somewhat.

In my experiments the shockwaves were measured, but this was not the focus of the work; since shock waves travel at the speed of sound of the material, ultrafast pulses are not required for their study. This may account for the dearth of articles found by your search.

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  • $\begingroup$ Dear Sir, Thank you for the answer and the reference, It is a simulation but there is one experiment I found in references. As I understood from your answer and by reading these references that the shock requires some buildup time and if the laser pulse is over before that the generated pressures are small due to onset of rarefaction. $\endgroup$
    – hsinghal
    May 6, 2016 at 6:12
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    $\begingroup$ @hsinghal: Simulations, based on appropriate physics, are often required to understand the details of complex interactions. There is often a computational physicist working with an experimental group these days, along with a collaborating theory group. $\endgroup$ May 6, 2016 at 14:01

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