Ngk Insulators, Inc.

Other

Osamu Mitomi

Kenji Aoki

Jungo Kondo

Atsuo Kondo

Yuichi Iwata

Tetsuya Ejiri

Akiyoshi Ide

Takashi Yoshino

Yasunori Iwasaki

Akira Hamajima

Takenori Ichigi

Masataka Yamashita

Masatsugu Oshima

Jun Okumura

Kazuhisa Yamamoto

Kiminori Mizuuchi

Minoru Imaeda

Tatsuo Kawaguchi

Yuji Hori

Keiji Matsuhiro

Makoto Minakata

Hiroki Kobayashi

An optical modulator includes an optical modulation substrate, an electrical length adjusting substrate, a package containing the substrates, and a plurality of input ports for inputting high frequency electrical signals. The optical modulation substrate includes a substrate body made of an electro-optic material, a ground electrode and a plurality of signal electrodes provided on the substrate body, optical waveguides propagating lights interacting with the signal electrodes, respectively, and electrode input ports inputting the high frequency electrical signals into the signal electrodes, respectively. The signal electrode includes an interacting part, an input end part provided between the electrode input port and interacting part, and a terminal part. The electrical length adjusting substrate includes conductive lines connected to the input ports for inputting the high frequency electrical signals, respectively. The conductive lines have electrical lengths different from each other for adjusting the phase differences among the ports.

Optical modulator

An optical waveguide device includes a substrate of a ferroelectric material, at least a pair of electrodesA,B provided on one main face of the substrate, and a channel-type optical waveguideA formed in a gapof the pair of the electrodes. The optical waveguideA has a curved part. A central line C of the gapis provided outside of a center line WC of the optical waveguide with respect to the center O of curvature of the curved part

Curved optical waveguide in gap between electrodes device

A first main face of a substrate of a dielectric single crystal is etched to form recesses in the substrate. A second main face of the substrate is mechanically processed to form a slab, so that the recesses pass through the substrate to form through holes.

Method of producing a slab type two-dimensional photonic crystal structure

An optical modulator componenthas a substratefor modulation made of an electro-optical material and having a joining face; an optical waveguideprovided in or on the substrateand having at least one pair of branched portions; and a radio-frequency interaction portionapplying a voltage on the respective branched portionsto modulate light propagating through the branched portions. The optical waveguidehas end facesA,B,C andD present on the joining faceof the substratefor modulation.

Optical modulator component and optical modulator

An optical modulatorhas a supporting substrate, a modulating substratemade of an electro-optical material, an optical waveguideprovided on the side of a first main surfaceof the modulating substrate, and an adhesion layeradhering a second main surfaceof the modulating substrateonto the supporting substrate. The modulating substratehas a high-frequency interaction portionapplying a voltage on the optical waveguideto modulate propagating light, an incident portioninputting light to the optical waveguide, and an outgoing portionoutputting light from the optical waveguide. The high-frequency interaction portionis recessed on the first main surfaceof the modulating substratewith respect to the incident and outgoing portionsand. The high-frequency interaction portionhas a thickness smaller than the those of the incident and outgoing portionsand

Optical modulators

The invention provides an optical phase modulator having a substrate made of an electro-optical material, a signal electrode provided on the substrate and first and second ground electrodes provided on both sides of the signal electrode. The electrodes are provided so that a size of the first gap between the first ground electrode and the signal electrode is smaller than a size of a second gap between the second ground electrode and the signal electrode. Furthermore, an optical waveguide is provided in the first gap as an optical phase modulator and not provided in the second gap. A driving voltage required for the phase adjustments is thereby lowered, the impedance matching is easily made and excellent radio frequency property can be realized.

Optical phase modulator

An object of the present invention is, in an optical modulator, to increase the production yield by enhancing the patterning accuracy of the electrodes, as well as to reduce the electrode loss by increasing the thickness of the electrodes. An optical modulator has a substratemade of an electro-optical material; a modulation electrodeA,A,B provided on the substrate; and an optical waveguideprovided on the substrate. Light propagating through the optical waveguideis modulated by applying a modulation voltage to the modulation electrode. At least a part of the modulation electrode includes a baseformed on the substrateand a projection parthaving a width narrower than that of the base.

An object of the present invention is to widen the band of the velocity matching frequency as well as to reduce the electrode loss in the modulation electrode. An optical modulator has a substrate made of an electro-optical material, a signal electrodeA,B and a ground electrodeA,B provided on the substrate, an optical waveguide provided on the substrate. The signal electrode and the ground electrode each has an interaction sectionand a feed-through section. Light propagating through the optical waveguide is modulated by applying a modulation voltage on the interaction section. The thickness of the feed-through section is greater than that of the interaction section.

It is provided a radio oscillating system for oscillating a radio signal. The system has an optical modulator for oscillation, a modulating means for inputting a modulating signal of a frequency of fm into the optical modulator to modulate a carrier wave so as to interpose sideband waves onto the carrier wave at positions shifted with respect to the frequency of the carrier wave by the frequency 'fm'; and an optical receiver for oscillation for receiving beam from the optical modulator and converting the beam into an electrical signal. The system further has a radiating means for radiating radio signal of a frequency of 2fm based on the electrical signal. An input voltage Vp-p applied on the optical modulator is 1.0 times or more and 1.99 times or less of a half-wavelength voltage V&#x3c0; of the optical modulator.

Radio oscillating and radar systems

An optical modulator having an optical modulation part and a connection part for an optical fiber propagating light. The optical modulation part has a modulation substrate of an electro-optic material, a modulation optical waveguide formed on the modulation substrate, a high frequency interaction part for applying a voltage to the modulation optical waveguide to modulate the propagation of light, a first supporting substrate and a first adhesion layer for adhering the modulation substrate to the first supporting substrate. The connection part has a connection substrate of an electro-optic material, a connection optical waveguide formed on the connection substrate, a second supporting substrate, and a second adhesion layer for adhering the connection substrate to the second supporting substrate. The modulation substrate is adhered to the connection substrate. The first supporting substrate is adhered to the second supporting substrate. The modulation optical waveguide is connected to the connection optical waveguide.

An optical modulator has an optical waveguide substrate having a pair of principal surfaces, a pair of side surfaces an incident face and exit face of light, the substrate being composed of a ferroelectric material; a channel optical waveguide having at least a pair of branch sections, a multiplexing section of the branch sections and an exit section provided on the downstream of the multiplexing section, the waveguide being formed on the principal surface of the optical waveguide substrate; a modulation electrode electrodes for applying a signal voltage for modulating light propagating in the branch sections; and a reflective groove for reflecting leaked light of off-mode emitted from the multiplexing section and emitting the light from a principal surface of the optical waveguide substrate. An operating point of the optical modulator is controlled by changing a DC bias applied on the modulation electrode based on optical output of the leaked light of off-mode.

An optical modulator is provided for modulating light propagating in a three-dimensional optical waveguideby applying a voltage thereto. The optical modulator has the three-dimensional optical waveguideincluding at least one pair of branch optical waveguidesand, a multiplexing partof the branch optical waveguides and an emission partprovided in the downstream of the multiplexing part, modulation electrodesA,B andfor applying a signal voltage for modulating light propagating in the three-dimensional optical waveguide, and guiding waveguidesA andB for guiding primary mode light from the multiplexing part. Thickness of the substrate is 20 &#x3bc;m or less at least under the modulation electrodes, and an operation point of the optical modulator is controlled by changing, based on light output from the guiding waveguides, DC bias applied onto the modulation electrodes.

Optical Modulator

An optical waveguide structure has a slab type photonic crystal and an optical waveguide provided in the photonic crystal. The photonic crystal has a slab of a dielectric film and a plurality of lattice columns each having dielectric pillars. The dielectric pillars included in the lattice columns at least in n'th order (n represents 1, 2, 3, 4 and 5) in distance with respect to said optical waveguide, respectively, has a planar shape of an equilateral polygon or exact circle. At least one of the dielectric pillars included in the lattice columns at least in n'th order (n represents 2, 3, 4 and 5) with respect to the optical waveguide has a size rn different from a fundamental size ro.

Optical waveguide structures

An optical functional device has a slab type two-dimensional photonic crystal layer. The photonic crystal layer has a dielectric layer and a plurality of lattice columns each comprising dielectric pillars. A waveguide portion is provided in the photonic crystal layer. A ground electrode and a signal electrode are formed on the dielectric layer for applying a modulating voltage on light propagating in the waveguide portion. A layer of a high dielectric constant is laminated on the dielectric layer. A low dielectric portion is formed direct under the waveguide portion and the lattice columnsA,B andC of at least first, second and third orders in distance with respect to said waveguide portion.

Optical functional devices

The present invention provides an optical waveguide device having a configuration such that the optical waveguide is folded back on an end area of the optical waveguide substrate to widen the modulation band. The optical waveguide deviceA includes a substrate bodymade of an electro-optical material, optical waveguide, and modulation electrodesandfor applying a voltage on the optical waveguide. The optical waveguideincludes first primary areasand, a first curved areaA, first folding-back areasandprovided between the first curved areaA and a folding-back point, second primary areasand, a second curved areaB, and second folding-back areasandprovided between the second curved areaB and the folding-back point. At least a part of the signal electrode is provided in a folding-back region extending from the first curved areaA and the second curved areaB to the folding-back point

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Nagoya, Japan

Osamu Mitomi