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Self-Focusing and Nonlinear Effects
Chapter 4
4. Self-Focusing and
Nonlinear Effects
Vitaly Gruzdev
4.1 Introduction
Scaling of rate of laser-induced eects with laser irradiance* (i.e., surface density of power;
W/cm
2
) is one of the fundamental features that control dynamics of laser–material interac-
tions. At low irradiance, the scaling is linear for most interactions: (1) zero irradiance pro-
duces zero rate, and (2) increase in irradiance by factor of K leads to increase in rate by factor
of K (Figure 4.1). ose properties of the linear scaling are mathematically expressed as follows:
I
, (4.1)
where
R is the rate of an eect
I is the laser ...