We are investigating the nonlinear optical properties of noble metal nanoparticles immersed in various host materials. Changes in the permittivity of the nanoparticles under large irradiances are measured in pump-probe experiments. A two-temperature model is used to fit the data and obtain a correlation between the electron gas and lattice temperatures and the Drude-type electron damping of the metal. The enhanced two-photon absorption (2PA) of silver nanospheres suspended in carbon disulfide (CS2) is measured by Z-Scan. The sample showed a combined signal of 2PA and saturable absorption (SA) which can be decoupled using the temperature-electron-damping mapping.
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