Two-photon polymerization using femtosecond laser

<p>The demand for microfabrication by laser technology has been the foundation of the new age of three-dimensional micro-structuring processes. One of these new processes  that has been established in recent years has been the two-photon polymerization (2PP) technique by femtosecond lasers. Unlike the well known stereo-lithography (SL), this newly developing technology provides simple and rapid fabrication procedures and demonstrates much better quality and structural resolution. In addition, by using computer generated 3D models, this technique can produce any kind of 3D structures that can be then fabricated and integrated into complicated devices. Currently used strategies and methods to produce the smallest possible feature by using 2PP process are acceptable but the strive for enhanced results is necessary in order to continue the progression of such technique This thesis proposes a broader knowledge on laser parameters that affect 2PP process and the implementation of such parameters in order to produce the smallest feature size and the highest aspect ratio structure possible. A high repetition rate, high power femtosecond laser is investigated for exceeding the quality demand established by the current market. An experimental study of the proposed laser system and the analysis of control parameters, such as laser power and repetition rate, are presented. The influence of pulse width, laser power, substrate material, and scanning speed on aspect ratio is  analyzed in detail. The produced micro-structure with the measured aspect ratio indicates the capability of meeting the quality and requirements that have been established by the current market.  </p>