Marek Samoc1 Marcin Nyk1 Jan Zareba1 Adrian Justyniarski1

1, Wroclaw Univ Sci Tech, Wroclaw, , Poland

Typically, various nonlinear optical effects are investigated in materials in the form of inorganic or polymer glasses, liquid solutions, single crystals or nanoparticles, the notable exception being powder SHG studies. On the other hand, there exist classes of materials such as metal-organic frameworks (MOFs) that are mostly available in the form of crystalline powders. It appears that their NLO properties may also be of interest, for example some MOFs are very efficient multiphoton absorbers showing also quite high values of the luminescence quantum yields. Exploitation of multiphoton induced luminescence of MOFs is an example of the concept of application of NLO materials in the form of "NLO pigments": materials that must be used in the solid state form but the intended application allows for the use of microcrystalline powders.