Femtosecond Laser Micro-and Nano-fabrication Technique And Application Researches

Ultrahigh peak intensity can be achieved at low pulse energy of femtosecond (fs) laser. Three dimensional microfabrication with high precision can be achieved by the ablation of solid material and two-photon photopolymerizatin (TPP) of photosensitive resin. Fs laser micro- and nano-fabrication is a focus in fs laser field.The studies of the fs laser propagating and focusing in medium are theoretical foundation of the fs laser micro- and nano-fabrication. Paraxial focus of Gaussian beam was resolved by paraxial approximation method, influence of self-focusing and plasma on focusing was discussed and the objective lens with free numerical aperture was achieved by adjusting the diameter of laser beams.Fs laser micro- and nano-fabrication system was established. Then, nonlinear ionization mechanism was investigated of the interaction between fs laser and K9 glass. The micron and sub-micron structures on K9 glass surface and arbitrarily three dimensional body fabrications were carried out, for example, all kinds of miniature structure arrays on the surface and diversified photonic devices within.TPP theoretical model was founded, and the polymeric threshold and the lateral resolution were deduced. Fs laser direct scanning 3D fabrication system was set up. TPP was achieved in ORMOCER resin, with the resolution less than the diffraction limitation. With TPP, some typical complex biological apparatuses were fabricated.2D photonic crystal (PC), 2D PC waveguide and high quality 3D PC were fabricated by fs laser TPP in photosensitive resin. Qualitative analysis of the fabrication error of 3D logpile PC was investigated.