Two-photon excitation provides a means of activating chemical or physical processes with high spatial resolution in three dimensions and has made possible the development of three-dimensional fluorescence imaging, optical data storage, and lithographic microfabrication. These applications take advantage of the fact that the two-photon absorption probability depends quadratically on intensity, so under tight-focusing conditions, the absorption is confined at the focus to a volume of order λ3 (where λ is the laser wavelength). Any subsequent process, such as fluorescence or a photoinduced chemical reaction, is also localized in this small volume. Although three-dimensional data storage and microfabrication have been illustrated using two-photon-initiated polymerization of resins incorporating conventional ultraviolet-absorbing initiators, such photopolymer systems exhibit low photosensitivity as the initiators have small two-photon absorption cross-sections (δ). Consequently, this approach requires high laser power, and its widespread use remains impractical. Here we report on a class of π;-conjugated compounds that exhibit large δ (as high as 1, 250 × 10−50 cm4 s per photon) and enhanced two-photon sensitivity relative to ultraviolet initiators. Two-photon excitable resins based on these new initiators have been developed and used to demonstrate a scheme for three-dimensional data storage which permits fluorescent and refractive read-out, and the fabrication of three-dimensional micro-optical and micromechanical structures, including photonic-bandgap-type structures.

Two-photon polymerization initiators for three-dimensional optical data storage and microfabrication

In the present study, we report synthesis, characterization, structural and theoretical studies of two copper(II) complexes, [Cu(py)2(L1)2] (1) and [Cu(phen)(Ac)2-Cu2(Ac)4]n (2), and a nickel(II) c...

Synthesis, characterizations, crystal structures, and theoretical studies of copper(II) and nickel(II) coordination complexes

Synthesis, spectral characterization, DFT, molecular docking and biological evaluation of some newly synthesized asymmetrical azines of 3,5-dimethoxy-4-hydroxy benzaldehyde

The title compound (E)-N’-(4-chlorobenzylidene)-4-fluorobenzohydrazide monohydrate (CBFBH) is a novel hydrazone Schiff base compound, synthesized and characterized by FTIR, 1H and 13C NMR, UV-Vis a...

Structural, theoretical and third order nonlinear optical properties of (E)-N’-(4-chlorobenzylidene)-4-fluorobenzohydrazide monohydrate

A Review: An Overview on third-order nonlinear optical and optical limiting properties of Schiff Bases

Single crystals of N’-[(E)-(4-bromophenyl) (phenyl) methylidene]–4-methylbenzenesulfonohydrazide (4BBTH), having potential applications in nonlinear electro optic field. The structure is elucidated...

Structural, theoretical, and third-order nonlinear optical investigations of N’-[(E)-(4-bromophenyl)(phenyl)methylidene]–4-methylbenzenesulfonohydrazide

P. Srinivasan

Papers

Structural, theoretical, and third-order nonlinear optical investigations of N’-[(E)-(4-bromophenyl)(phenyl)methylidene]–4-methylbenzenesulfonohydrazide