Nippon Telegraph and Telephone Corporation

Nippon Telegraph and Telephone Public Corporation

Kaikiu Kogyo Co. Ltd.

Toshikuni Kaino

Satoru Tomaru

Takashi Kurihara

Michiyuki Amano

Shigeo Nara

Yuhei Mori

Nobuyuki Tomihashi

Akira Ohmori

Kaname Jinguji

Makoto Hikita

Yoshito Shuto

Shiro Matsumoto

Itaru Yokohama

Shigeru Oikawa

Michiya Fujiki

Hirohisa Kanbara

Kazuo Ishiwari

Kenichi Kubodera

Atsushi Yokoo

Sumiko Yuhara

Of hydrogen atoms constituting 2-adamantylamino-5-nitropyridine, at least hydrogen atom of N--H part is substituted with deuterium to obtain a deuterated AANP. An organic optical material is made from the deuterated AANP. Content of the deuterated AANP in this case is preferably more than 25%. With this method, an organic nonlinear optical material can be provided for devices having a large wavelength conversion efficiency in wavelength conversion relating to optical communications wavelength region, particularly at and around 1.55 .mu.m wavelength.

Deuterated 2-adamantylamino-5-nitropyridine, organic nonlinear optical

A third-order nonlinear optical main chain polymer material contains a high .chi..sup.(3) component having no less than 3 but no more than 7 .pi.-conjugated bonding groups and having an electron donor in the main chain of the polymer through covalent bonds. The donor is preferably an alkylamino structure, more preferably a dialkylamino structure. Particularly preferred is a diethylamino structure. The high .chi..sup.(3) component is preferably a phenylene ring system of which phenylene rings are bonded through azo bonding groups with the phenylene rings and the azo bonding groups being positioned alternately. The polymer main chain is polyurethane or polyester. The third-order nonlinear optical main chain polymer material is prepared by polyaddition of a high .chi..sup.(3) compound, i.e., a precursor of the high .chi..sup.(3) component, having a hydroxyl group at each end with a diisocyanate compound or by polycondensation of the high .chi..sup.(3) compound with a dicarboxylic acid.

Third-order nonlinear optical main chain polymer material and method for

The present invention provides a second-order nonlinear optical polymer including a polymer backbone and side groups bonded to the polymer backbone, wherein the side groups include one or more of a first nonlinear optical group represented by the following formula (C-1) and one or more of a second nonlinear optical group represented by the following formula (C-2) or (C-2)': ##STR1## wherein .pi..sub.1 to .pi..sub.n, .pi.'.sub.1, .pi.'.sub.2, and .pi.'.sub.1 each represent independently a .pi.-conjugated cyclic compound group; X.sub.1 to X.sub.n-1, X'.sub.1, Y.sub.1 to Y.sub.n-1, and Y'.sub.1 each represent independently CH, N, or N.fwdarw.O; A.sub.1, A.sub.2, and A.sub.3 each represent independently an electron attracting group; D.sub.1, D.sub.2, and D.sub.3 each represent independently an electron donating group; and n represents an integer of 3 or greater.

Second-order nonlinear optical polymer and method for producing the same

An organic nonlinear optical device having a nitrostyrene compound represented by a formula: ##STR1## wherein R.sub.1 is an ethyl group R.sub.2 is a group selected from the group consisting of an acryloyloxyethyl group (CH.sub.2 .dbd.CH--COO--CH.sub.2 CH.sub.2 --) and a methacryloyloxyethyl group (CH.sub.2 .dbd.C(CH.sub.3)--COO--CH.sub.2 CH.sub.2 --); and X.sub.1, X.sub.2, X.sub.3, and X.sub.4 are the same or different and each is selected from the group consisting of a hydrogen atom, a hydroxyl group, a halogen atom, an alkyl group, an alkoxy group, an alkyl ester group, and an alkylamide group, is provided.

Organic nonlinear optical material and nonlinear optical device

Plastic optical fibers comprising as a core component a polymer predominantly containing methyl methacrylate and as a cladding component a copolymer lower in the refractive index than the core component, the plastics optical fibers being characterized by performing conjugate spinning with use of the cladding component which is vinylidene fluoride-tetrafluorethylene copolymer having incorporated therein 5 to 50% by weight of a polymer predominantly containing methyl methacrylate.

Plastics optical fibers

In a sealed system, a polymerization initiator and a chain transfer agent are added to a methyl methacrylate monomer distilled under reduced pressure condition via a distillation step of the former both ingredients, the methyl methacrylate monomer is successively polymerized to prepare a core polymer while maintaining the reduced pressure condition, then the resulting core polymer is subjected to melt spinning to form a core fiber while maintaining the sealed system, and a clad of a macromolecular compound having a refractive index lower than that of the aforesaid core fiber is adhered around the periphery thereof, whereby a low-loss plastic optical fiber with excellent optical transmission characteristics having a core-cladding structure is fabricated. Plastic optical fibers so made exhibit light attenuation as low as 60 dB/km or lower.

Fabrication of a low-loss plastic optical fiber

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Mito, Japan

Toshikuni Kaino