Two-photon 3D microfabrication

While a more detailed review of two-photon 3D microfabrication can be found in another chapter of this issue, this chapter will concentrate on our work on characterization and apphcation of commercial photoinitiators. The development of better 2PA photoinitiators would be expected to facilitate 3D photopolymerization technologies. Efficient 2PA compoimds based on phenylethenyl constructs bearing electron-donating and/or electron-withdrawing moieties have been reported [105-107]. Among these are electron-rich derivatives that have been found to undergo a presumed two-... 

In addition to these examples, an electron-transfer free radical photoinitiator H-Nu 470 (5,7-diiodo-3-butoxy-6-fluorone) has been also successfully used for 3D microfabrication by near-IR two-photon induced polymerization... 

The field of laser lithography (also often called laser microfabrication) branched out from multiphoton excitation microscopy and has become established during the last decade. The principles of two-photon microscopy, which has enabled high-resolution 3D imaging [3,4] and optical memory [5], were gradually adapted for 3D laser hthography [6]. A relevant collection of seminal papers on the field can be found in [7]. 

Zhou W, Kuebler SM, Braun KL, Yu T, Ober JKC, Ober CK, Perry JW, Marder SR (2002) An efficient two-photon-generated photoacid applied to positive-tone 3D microfabrication. Science 296 1106-1109... 

Two-photon three-dimensional (3D) micro- and nanofabrication using a femtosecond laser have been used to create various types of 3D micro- and submicrometer structures [70, 74, 260, 265, 574], A microscope with axial (z) and lateral (r) resolutions given by Eqs. (77) and (78) was used for laser microfabrication [574]. Wavelength of irradiation light (/.), refractive index of the material (/ ), and numerical aperture of the objective lens (NA) influence the resolution in axial and lateral directions. 

NLO transmission, and 3D microfabrication. However, there have been rather few studies of organometallic compounds at this time, especially studies in which two-photon spectra have been determined. 

---