Polarization controlled semicondcutor photonic devices by strainedbarrier superlattice structures AIP Conf. Proc. 227, 184 (1991); 10.1063/1.40649 Surface chemistries and electronic properties of molecular semiconductor thin films grown by effusion beams AIP Conf.

The surface deformation induced by a Gaussian laser beam on azobenzene polymer film reveals strong polarization dependence and establishes that an optical field component in the direction of the intensity gradient is essential for the deformation process. The experimental results allow us to infer the phase relationship between the surface relief gratings and the writing interference pattern.

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Over at least the past decade, there has been considerable interest in the introduction of specific side groups into polydiacetylenes (PDA, 1) to control properties such as polymer chemical reactivity, 1 electronic structure, 1,2 and spectroscopy, 3 second-order nonlinear optical (NLO) properties, 4 and chromic phenomena. 5 In recent reports from our laboratories, 6 the synthesis, acentric self-assembly, and second-order NLO properties of the PDA of the n-butoxycarbonylmethylurethane (BCMU) of 1-(5-pyrimidyl)-1,3-octadiyn-8-ol (BPOD, 2a) point to a design paradigm that merits elaboration. In particular, we note three design features: (1) a conjugated backbone; (2) one side group as a chromophore; (3) the other side group with both aliphatic and hydrogenbonded urethane groups to promote solubility and processability. The polymer was found to spontaneously self-assemble into an acentric order with significant second-order optical nonlinearity. We now report the synthesis of the alkoxycarbonyl-methyl urethanes of 9-(N-methyl-N-phenylamino)-5,7-nonadiyn-1-ol (2b,c) and their polymerization. We find that the polymers are soluble and processable and that the benzenoid ring group is susceptible to many of the substitution reactions expected for aromatic amines making it a more versatile system for chemical modification than the previously investigated systems. 1 We further describe novel self-assembling and linear and nonlinear optical properties of the modified polymers. These polymers, in addition to possessing the unusual assembly properties of PDA-BPOD, present some unique processing features. The azobenzene-functionalized PDA from 2b, for example, was photofabricated to produce regular surface relief gratings. We conclude that the PDA from 2b,c and their functionalized forms comprise the most versatile PDA system reported to date, in terms of chemical richness and diverse optical properties.The synthesis of 2b,c is illustrated in Scheme 1. Cadiot-Chodkiewicz coupling of N-methyl-N-propargylaniline and 5-bromohexyn-1-ol leads to 9-(N-methyl-N-phenylamino)-5,7-nonadiyn-1-ol (2d) in 74% yield. Reaction of this diacetylene alcohol with the appropriate isocyanate leads to 2b,c; the yield of 2b is 73%.2b,c are viscous yellow oils at ambient temperature and did not polymerize in that phase on exposure to ultraviolet light. Crystallization was achieved as they were frozen in dry ice in evacuated ampules and polymerized in the solid state by exposure to 46 Mrad 60 Co γ radiation at a dose rate of 0.5 Mrad/h. The PDA from 2b,c, obtained in approximately 40% yield after monomer removal, are red-colored solids that are found to be soluble in a manner similar to PDA-BPOD and -BCMU in solvents such as chloroform and N,Ndimethylformamide (DMF) with an absorption maximum at 473 nm (CHCl 3 ). The 13 C NMR and Raman 2a,b spectra of the PDA from 2b,c verify the assignment of the usual enyne backbone structure, and gel permeation chromatography of a chloroform solution of the PDA of 2b reveals (relative to polystyrene) M w 190 000, ...

A new class of all organic sol‐gel second‐order nonlinear optical (NLO) materials based on hexa(methoxymethyl) melamine (HMM) was developed. Two NLO active chromophores, 4 (4′‐nitrophenylazo) aniline (DO3) and 4‐amino‐4′‐nitrobiphenyl (ANB), were incorporated into the melamine matrices. The samples exhibited second‐order optical nonlinearity after poling and curing at 220°C for 30 min. DO3/HMM and ANB/HMM samples showed a second harmonic coefficient, d33 of 10.7 and 1.8 pm/V at 1064 nm, respectively. The temporal stability of both systems was studied at room temperature as well as at 100°C. Waveguide optical losses of samples at 633 and 830 nm were found. © 1995 John Wiley & Sons, Inc.