Abstract

We present a study of laser-induced optical inhomogeneity and associated nonlinear phenomena in a liquid suspension. The investigated medium consists of nonlinear dielectric particles (refractive index, n_p = n_0p + n_2pZ) suspended in a linear liquid (refractive index n₀₁) with n_0p = n₀₁, where / is the incident irradiance. When / is low, the medium is transparent. When / is high, a mismatch An = n_2pl is induced between the particles and the liquid, which leads to scattering of the laser beam and low transmission. Moreover, the nonlinearity of the particles causes an irradiance- dependent phase change of the laser beam, which leads to self-focusing or defocusing of the beam. With a proper lens and aperture system outside the liquid cell, the transmission can be further reduced (from the occurring through scattering loss alone) by taking advantage of the self-refraction.

© 1986 Optical Society of America