Two-photon absorption (TPA) has been a useful tool in spectroscopy. With the progress of laser technologies, excitation of various photochemical and physical reactions by two or multiphoton processes becomes essential for advanced microscopic imaging, nano-spectroscopy and laser materials processing. In our research, we use TPA to excite local photopolymerization of resins, by which various photonic and micro-mechanical devices and systems have been produced. In this paper, we will summarize our recent progresses including: improvement of three-dimensional (3D) spatial resolutions and their characterization by an ascending scan method, a strategy of shortening fabrication duration, and a 3D rnicro-diagnosis technology. (C) 2002 Published by Elsevier Science B.V.