The two photon absorption (TPA) process is currently used to write high resolution microstructures that can be used in micro-electro-mechanical system (MEMS) and photonic crystal application. Key parameters required to predict the final structure formation for this process are experimentally determined and reported in this thesis for two commercially available resists, Ormocore and SU-8. Moreover, writing capability of 3D structures with simple features is demon­strated in this work. The TPA coefficients of resists were measured for 800 nm (wavelength) light. Light source with such...