Nippon Telegraph and Telephone Corporation

Toray Industries, Inc.

Ken-ichi Kubodera

Tetsuya Gotoh

Keiichi Egawa

Tosiyuki Kondoh

Takayoshi Hayashi

Shiro Matsumoto

Two optical waveguides comprising a light transmitting medium are disposed close to each other on a substrate, and electrodes are disposed parallel to each other so as to sandwich one optical waveguide. The light transmitting medium is formed by dispersing fine droplets of a liquid crystal in a light transmitting material, such as glass or polymer, the liquid crystal fine droplets having droplet diameters of about one digit smaller (that is, about an order of magnitude smaller) than the wavelength of light. Linearly polarized light having a plane of polarization in a direction parallel to the direction of application of voltage to the optical waveguide, i.e., in the direction of the substrate surface, is fed as input lights into the optical waveguides. Upon application of voltage, the refractive index of one optical waveguide changes, while the refractive index of the other optical waveguide remains unchanged. Hence, the coupling ratio changes, achieving an optical switch. Thus, the present invention can provide a practical optical processing method which utilizes the large refractive index anisotropy and the low-voltage response of a liquid crystal, and a waveguide type optical device which can be used preferably for this method.

Optical processing method using fine liquid crystal droplets and

A third-order nonlinear optical element showing wide employable wave-length range of input light, high speed operation and low light intensity of input light is disclosed. The third-order nonlinear optical element of the present invention has at least two substantially optically smooth surfaces and comprise a charge-transfer complex consisting essentially of (i) at least one electron-accepting component selected from the group consisting of cyano compounds, quinones, nitro compounds, acid anhydride, halogenes, and halogenated carbons; and (ii) at least one electron-donating component selected from the group consisting of unsaturated cyclic hydrocarbon compounds, unsaturated heterocyclic compounds, chalcogen-containing compounds, quarternary unsaturated heterocyclic compounds and metals. The charge-transfer complex of nonlinear optical element of the present invention is formed of said at least one electron-accepting component and said at least one electron-donating component in the ground state and at least one of said components is an organic compound having .pi.-conjugated system.

Method of operating third-order nonlinear optical element

A third-order nonlinear optical element showing wide employable wave-length range of input light, high speed operation and low light intensity of input light is disclosed. The third-order nonlinear optical element of the present invention has at least two substantially optically smooth surfaces and comprise a charge-transfer complex consisting essentially of (i) at least one electron-accepting component selected from the group consisting of cyano compounds, quinones, nitro compounds, acid anhydride, halogenes, and halogenated carbons; and (ii) at least one electron-donating component selected from the group consisting of unsaturated cyclic hydrocarbon compounds, unsaturated heterocyclic compounds, chalcogen-containing compounds, quarternary unsaturated heterocyclic compounds and metals The charge-transfer complex of nonlinear optical element of the present invention is formed of said at least one electron-accepting component and said at least one electron-donating component in the ground state and at least one of said components is an organic compound having .pi.-conjugated system.

Growing community of inventors

Isehara, Japan

Ken-ichi Kubodera