Fuji Photo Film Company, Limited

Kozi Kamiyama

Yoji Okazaki

Hiroshi Sunagawa

Nobuharu Nozaki

Masaki Okazaki

Jin Murayama

Seiiti Kubodera

Masami Hatori

Chiaki Goto

Toshio Iijima

Shinsuke Umegaki

Syozo Takeuchi

An optical deflecting apparatus comprises a first generator for generating a first surface acoustic wave which advances to intersect an optical path of a guided optical wave advancing inside of an optical waveguide and diffracts and deflects the guided optical wave, and a second generator for generating a second surface acoustic wave which advances to intersect the optical path of the guided and diffracted optical wave and diffracts and deflects the guided and diffracted optical wave in a direction that amplifies the deflection caused by the diffraction. The first and second surface acoustic wave generators are formed to continuously change the frequencies of the first and second surface acoustic waves and the directions of advance thereof while satisfying the conditions of k1+k1=k2 and k2+k2=k3 wherein k1 and k2 respectively denote wave vectors of the guided optical wave before and after being diffracted by the first surface acoustic wave, k3 denotes the wave vector of the guided optical wave after being diffracted by the second surface acoustic wave, and k1 and k2 respectively denote wave vectors of the first and second surface acoustic waves.

Variable acoustical deflection of an optical wave in an optical waveguide

An optical wavelength conversion device is composed of a nonlinear optical material, and a first cladding layer having a refractive index lower than the refractive index of the nonlinear optical material and covering the nonlinear optical material, thereby to convert a fundamental wave entering the optical wavelength conversion device to a second harmonic, to guide the second harmonic through the first cladding layer, and to radiate the second harmonic. A second cladding layer formed of a material having a refractive index lower than the refractive index of the first cladding layer is provided outside of the first cladding layer, thereby to protect the first cladding layer.

Optical wavelength conversion device

A light modulator comprises a stack of a wave guide layer and an adjacent layer normally exhibiting a refractive index smaller than that of the wave guide layer, at least one of these layers being formed of a material whose refractive index changes by application of energy. An energy applicator is provided at least in one of these layers, and a dielectric grating is positioned at the surface of the adjacent layer over a section where energy is applied by the energy applicator. A drive circuit is provided for energizing the energy applicator and causing a change in refractive index to arise in the wave guide layer and/or the adjacent layer so that a wave guided inside of the wave guide layer is radiated out of the stack by interaction with the dielectric grating. In a wave guide device, the wave guide layer is formed of a thermo-optic material in which the thermal coefficient of refractive index is zero or negative, and the adjacent layer is formed of a thermo-optic material exhibiting a positive thermal coefficient of refractive index.

Light modulator and wave guide device

An optical wavelength conversion device is composed of an organic nonlinear optical material, and a cladding layer having a refractive index lower than the refractive index of the organic nonlinear optical material and covering the organic nonlinear optical material, thereby to convert a fundamental wave entering the optical wavelength conversion device to a second harmonic, and to radiate the second harmonic. At least one of device edge faces including edge faces of the organic nonlinear optical material is provided with a shielding layer for shielding the device edge face from ambient atmosphere, thereby to prevent the organic nonlinear optical material from sublimation and deterioration.

An optical wavelength conversion device is constituted by a pair of substrates disposed facing each other, and an optical waveguide formed of a nonlinear optical material and disposed between the substrates, thereby to convert a fundamental wave entering the optical wavelength conversion device formed to a second harmonic which is phase matched by Cherenkov radiation. At least one of the substrates is provided with a grating for entry of the fundamental wave, which is formed on a surface contacting the optical waveguide, and/or with a grating for radiation of the second harmonic, which is formed on a surface opposite to the surface contacting the optical waveguide. The optical wavelength conversion device is made by forming grooves on the substrates, filling a slight space between the substrates with a crystallizable organic nonlinear optical material, and gradually crystallizing the optical material.

Optical wavelength conversion device, and a method of making the same

A pick-up head for use with an optical information storage disk includes an optical waveguide, a light source, a waveguide lens, a focusing grating coupler, and a light detector. Wave light generated by the light source and propagated via the wave guide lens through the optical waveguide is deflected by a surface elastic wave generated by an inter-digital transducer. The inter-digital transducer is controlled by a tracking error signal to vary the frequency of the surface elastic wave to change the deflection angle of the wave light in order to eliminate any tracking error to which a light spot on the optical disk is subjected. Focusing control may be effected by a conventional focusing control mechanism or a bimorph driven by a focusing error signal.

Pick-up head for optical information storage disk

A light beam scanning system comprises a stack of a wave guide layer and an adjacent layer normally exhibiting a refractive index smaller than that of the wave guide layer, the wave guide layer and/or the adjacent layer being made of a material whose refractive index changes by the application of energy. Many energy application devices are positioned at the wave guide layer and/or the adjacent layer along an optical path of wave guided inside of the wave guide layer. Dielectric gratings are positioned on the adjacent layer so as to correspond to sections where energy is applied. A drive circuit is provided for sequentially and selectively energizing the energy application devices, and changing the refractive index of the wave guide layer and/or the adjacent layer so that the guided wave is radiated out of the stack by interaction with the dielectric gratings at the sections where energy is applied.

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Kanagawa, Japan

Kozi Kamiyama