Limitation of laser radiation power by carbon materials with a nonlinear optical threshold effect at a flat-top pulse shape

The possibilities of using multivariate determination of carbon nanotubes properties based on the dependence data of the normalized transmission logarithm on the sample displacement in the case of Z-scan with an open aperture as well as on the total pulse energy in the case of fixed sample position measurements are studied. The radiation transfer equation for the threshold dependence of the absorption coefficient on the intensity of a flat-top laser beam is used. The data of physical and computational experiments showed the sensitivity of the measured curves with respect to the values of the constants of the optical and threshold energy fluence, as well as the beam waist radius. The possibility of multivariate determination of the properties of liquid carbon nanotube-based dispersed media with a nonlinear optical threshold effect and beam waist radius inside such samples has been established. Keywords: optical limiting, multivariate analysis, carbon nanotubes, Z-scan