
19Laser-Induced Damage by Thermal Effects
Chapter 2
If damage is due to surface melting, then
dT = T
m
− T
a
,
where
T
m
is the temperature at which the surface melts
T
a
is the ambient temperature
It should be noted that the absorption is the sum of the intrinsic absorption and the
surface absorption. It has been proved that the roughness of the surface of a metal mir-
ror aects the absorption. It should be noticed however that the roughness needs to be
measured in terms of the wavelength of the incident laser radiation.
e expression
TT C
may be regarded as a gure of merit (FOM) for LID
of metal surfaces. It may however be modied by anomalo ...