http://nathan.instras.com/MyDocsDB/doc-705.pdf

Photopolymerization reactions under visible lights: principle, mechanisms and examples of applications

Photoinitiators for free radical polymerization

Covalent immobilization of chitosan/heparin complex with a photosensitive hetero-bifunctional crosslinking reagent on PLA surface.

Second harmonic generation and crystal growth of substituted thienyl chalcone

Several kinds of bromo substituted organic conjugation compounds
including chalcones, α-cinnamylideneacetophenones, benzophenones, stilbenes
and diphenylacetylenes have been synthesized, and their powder second harmonic
generation (SHG) efficiency, cut-off wavelength λcut-off
and thermal stability have been studied. Their molecular first-order hyperpolarizabilities β
were investigated by CNDO/S-CI semiempirical calculation methods. The results
reveal that the bromo group can obviously improve the molecular first-order
hyperpolarizabilities and can effectively reduce the dipole–dipole interactions
between the molecules. Thus the bromo group favors the acentric crystal structure,
and therefore the SHG effect of the material. The transparency and the thermal
stability of the materials can also be improved noticeably when the compounds
are substituted with a bromo group. In conclusion, the bromo group is an excellent
candidate group in designing effective organic second-order nonlinear optical
materials.

The important role of the bromo group in improving the properties of organic nonlinear optical materials

Several chalcone derivatives exhibiting second harmonic generation up to 5 times that of urea under IR-excitation have been synthesized by varying the substituents on both phenyl-rings.

Influence of the Ring-Substitution on the Second Harmonic Generation of Chalcone Derivatives

A large single crystal (18×40×15 mm3) of a new nonlinear optical material ‘‘chalcone derivative’’ has been grown by an evaporation method. This crystal was relatively easy to grow to a large size and was chemically stable. The cutoff wavelength was 430 nm. The calculated phase matching angles for the second‐harmonic generation (SHG) of Nd:YAG lasers agreed with the experimental data. Effective nonlinear optical coefficients deff of type I and type II for SHG have been measured to be 3.5 pm/V for type I and 5.7 pm/V for type II.

Laser properties of new organic nonlinear optical crystals chalcone derivatives

Crystal growth of 4-Br-4'-methoxychalcone and its characterization

It was found that poly[(4-azidophenyl)carbory)ethyl methacrylate] film irradiated by W light under an electric field showed larger second harmonic generation (SHG) than one without irradiation. This is the first photoactivatable nonlinear optical polymer. The increasee of SHG by irradiation was explained by the increase of the β value because a photoreaction changes the azido groups to amino and azo groups

Masaharu Nakayama

Papers

Second harmonic generation and crystal growth of substituted thienyl chalcone

Influence of the Ring-Substitution on the Second Harmonic Generation of Chalcone Derivatives

Laser properties of new organic nonlinear optical crystals chalcone derivatives

Crystal growth of 4-Br-4'-methoxychalcone and its characterization

Novel photoactivatable nonlinear optical polymers: poly[((4-azidophenyl)carboxy)ethyl methacrylate]