Zelensky S. Non-linear emission by light-absorbing centres in condensed matter

The dissertation is devoted to experimental investigation of non-parametric (non-coherent) nonlinear optical properties of condensed matter containing absorption centres under excitation with nanosecond-scale laser pulses (10 ns). The objects of investigation are solutions of luminescent molecules, suspensions of light-absorbing micro-particles and glasses with light-absorbing micro-inclusions, garnet crystals doped with neodymium ions, and oxide (borate) glasses doped with mercury-like ions. The following non-parametric nonlinear optical phenomena are studied: nonlinear luminescence (sublinear and superlinear), nonlinear absorption and extinction (saturated absorption, excited-state absorption, absorption by photoionization products, light-induced scattering, etc.), nonlinear scattering (scattering with intensity-dependent cross section) and laser-induced incandescence of micro-particles and micro-inclusions. The common feature of the investigated phenomena lies in the fact that their optical nonlinearity is caused by absorption of laser radiation in the absorption centres. The dissertation is devoted to investigation of micro-mechanisms of optical nonlinearities in the mentioned media.