Nonlinear transmission and reflection at a dielectric-carbon microparticle suspension interface

We have observed nonlinear reflection and transmission at a dielectric-carbon microparticle suspension interface. Nonlinear reflectivities of as much as 90% were measured using frequency-doubled, 5-ns Nd:YAG laser pulses. This result is attributed to laser-induced cavitation and the resulting refractive-index change in the carbon suspension that leads to total internal reflection at the interface. The fraction of energy that is not switched by total internal reflection undergoes additional nonlinear attenuation by nonlinear scattering.