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Photoconductivity and the electro-optic effect are observed when a carbazole type polymer is influenced by photorefractivity. A guest/host method produces high diffraction efficiencies to produce polymeric materials. Storage time is measured as a single minute, while the erase-write dynamics are distinguished by a few seconds, along with the identification of an absorptive grating. The second-order moieties are connected as a sidechain to determine the working of a polymeric photoconductor. The amorphous materials reveal photogeneration and transfer characteristics of carriers, which cannot be modified.

A new method is described for phthalocyanine (Pc) structural diversity and the incorporation of a functional group that has allowed the fabrication of solvent resistant Pc nanostructures formed by using a newly developed nanoimprint by melt processing (NIMP) technique, a variant of standard nanoimprint lithography (NIL). Copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC), a click chemistry reaction, is used as an approach to structural diversity in Pc marcocycles.

In the previous paper we demonstrated novel multiexcitons in a neutral mixed-stack charge-transfer solid. The lowest multiexciton, the biexciton, has recently been of interest also in the context of quasi-one-dimensional organic materials that are different from the mixed-stack solids. The nature and strength of the optical transition from the exciton to the two-exciton states is of importance in understanding photoinduced absorption as well as two-photon absorption. We show that within the diverse theoretical models that describe these different classes of materials, the excited state absorption from the optical exciton to the two-exciton states changes in a fundamental way upon the formation of the biexciton. The identical nature of the exciton absorption within these models is a consequence of one dimensionality. © 1996 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Optical excitation in a strongly neutral quasi-one-dimensional mixed-stack charge-transfer solid results in an exciton state, in which the electron and the hole are bound by electrostatic Coulomb interactions that are large compared to the one-electron hopping. We present a joint theoretical–experimental demonstration of a new class of collective excitations, multiexcitons or exciton strings, consisting of a string of several (more than two) bound excitons, in a prototype neutral charge-transfer solid. The stability of the multiexciton states arise from the combined effects of one dimensionality and strong Coulomb interactions. Theoretically, we show that in narrow band one-dimensional semiconductors with long range Coulomb interactions, the occurrence of stable 2-exciton string (biexciton) necessarily implies stable higher multiexcitons. Experimentally, evidence for the multiexciton strings is demonstrated by femtosecond pump–probe spectroscopy of anthracene pyromellitic acid dianhydride. Excellent qualitative agreement is found between the calculated and the measured differential transmission spectra. Photoinduced absorptions to the 2-exciton string at low pump intensity and to the 3-exciton string at high pump intensity are observed, in agreement with the theory of excited state absorption. The 2-exciton string is confirmed also by a direct two-photon absorption measurement. The binding energies of the 2-exciton and the 3-exciton strings are obtained from the experimental data. The larger binding energy of the 3-exciton is in agreement with theory. © 1996 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Presents a study that measured the third-order optical nonlinear susceptibilities of crystalline and amorphous thin films of 4-butoxy-carbonyl-methyl-urethane polydiacetylene. Methodology; Analysis of the absorption spectrum of the thin films; Effect of two-photon and three-photon resonant enhancement on the third harmonic generation of the thin films.

Examines the room-temperature optical nonlinearities of multiple quantum wells and integrated-mirror etalons. Investigation on semiconductor materials for potential applications in optoelectronic and all-optical devices; Experimental details; Result of the study.