D4\(σ\) curves described analytically through propagation analysis of transverse irradiance moments
nonlinear optics
Opt. Lett. 41, 2081–2084 (2016)
Abstract
The far-field changes in the beam width of an intense light beam propagating inside optical materials are investigated aiming the measurement of the nonlinear properties of the samples. The beam width is characterized in this Letter in terms of the transverse irradiance moments (TIMs) that allow an accurate description of the beam interaction and propagation. TIMs are rigorously related to the paraxial beam propagation parameters, and it is also possible to consider elliptical and astigmatic beams. Experimental data with very good signal-to-noise ratio were obtained for the reference materials carbon disulfide and fused quartz.