Laser-induced damage threshold

As with laser ablation, a number of borderline situations (defined via the so-called damage threshold , ablation threshold and plasma threshold ) can be considered in describing the interaction of a laser pulse with a surface to induce the ablation and plasma formation associated to laser-induced breakdown. Only the plasma threshold is discussed here, however, as the other two are shared by laser ablation and are dealt with in Section 9.2.2. 

By using a curved evanescent wave, one can, in principle, obtain focusing of an electron beam simultaneously with reflection. Of course, all these potentialities of laser-induced reflective electron optics should be the subject matter of future studies, specifically into the damage threshold of the materials used for the formation of the high-intensity femtosecond evanescent laser light waves. 

The Shockley surface states commonly found on many face-centered cubic (fee) (111) surfaces are occupied for ky = 0 (see also Chapter 5). The study of electron dynamics by time-resolved 2-PPE, however, is restricted to unoccupied states because the laser intensities required to induce a detectable change in the population of occupied states are close to the damage threshold of the sample. The Pd(lll) surface is one notable exception in which the Shockley surface state is found 1.35 eV above the Fermi energy Ep [75]. With time-resolved 2-PPE, the lifetime of this state was measured to 13 fs as shown in Figure 3.2.4.6 of Section 3.2.4.3... 

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