The Laboratory of Nonlinear Optics of the Photonics Group studies nonlinear refraction and absorption in materials using Z-scan, pump/probe and multi-photon excited fluorescence. Ultrashort laser pulses are used to study the sepctrum of optical nonlinearities in organic materials, polymers and special glasses, which are potential candidates for photonic devices. The results obtained with these techniques, allied to other ones obtained uisng complementary methods, such as linear absorption, luminescence and quantum chemical calculations allow determining a relationship between the molecular structure and the nonlinear optical properties, as well as fundamental aspects of the nonlinearities.
The laboratory counts with Ti:Sapphire laser amplifier systems (mJ and kHz), delivering fs-pulses at 800 nm. Wavelenght tunnability is acchieved by means of Optical Parametric Amplifiers pumped by the Ti:Sapphire laser.