Abstract: It is provided a device for detecting an accumulation amount of particulates. The device has a filter for trapping particulates from a gas containing the particulates, a container 5 for containing the filter, an upstream pipe 3 provided on the upstream side of the container 5 to lead the gas into the container 5, a downstream pipe 4 provided on the downstream side of the container 5 to lead the gas after passed through the filter, a transmitting antenna 10 provided within the downstream pipe 4 to transmit an electromagnetic wave having a frequency of 30 GHz or more but not exceeding 10 THz, and a receiving antenna 11 provided within the upstream pipe 3 to receive the electromagnetic wave. An amount of the particulates trapped in the filter is detected based on an intensity of the electromagnetic wave received by the receiving antenna 11.

Abstract: 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? of the optical modulator.

Abstract: 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 electrode 3A, 3B and a ground electrode 2A, 2B provided on the substrate, an optical waveguide provided on the substrate. The signal electrode and the ground electrode each has an interaction section 2a, 2c, 3a, 3c and a feed-through section 2b, 2d, 3b, 3d. 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.

Abstract: 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.

Abstract: 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 2 fm 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? of the optical modulator.

Abstract: 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.

Abstract: An optical modulator is provided for modulating light propagating in a three-dimensional optical waveguide 5 by applying a voltage thereto. The optical modulator has the three-dimensional optical waveguide 5 including at least one pair of branch optical waveguides 5c and 5d, a multiplexing part 5e of the branch optical waveguides and an emission part 5f provided in the downstream of the multiplexing part, modulation electrodes 3A, 3B and 4 for applying a signal voltage for modulating light propagating in the three-dimensional optical waveguide 5, and guiding waveguides 6A and 6B for guiding primary mode light from the multiplexing part. Thickness of the substrate is 20 ?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.

Abstract: 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.

Abstract: 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.

Abstract: An optical modulator component 2 has a substrate 4 for modulation made of an electro-optical material and having a joining face 4b; an optical waveguide 6 provided in or on the substrate 4 and having at least one pair of branched portions 6c; and a radio-frequency interaction portion 11 applying a voltage on the respective branched portions 6c to modulate light propagating through the branched portions. The optical waveguide 6 has end faces 15A, 15B, 15C and 15D present on the joining face 4b of the substrate 4 for modulation.

Abstract: An optical modulator 24 has a supporting substrate 5, a modulating substrate 11 made of an electro-optical material, an optical waveguide 12 provided on the side of a first main surface 30 of the modulating substrate 11, and an adhesion layer 6 adhering a second main surface 31 of the modulating substrate 11 onto the supporting substrate 5. The modulating substrate 11 has a high-frequency interaction portion 11c applying a voltage on the optical waveguide 12 to modulate propagating light, an incident portion 11a inputting light to the optical waveguide, and an outgoing portion 11b outputting light from the optical waveguide. The high-frequency interaction portion 11c is recessed on the first main surface 30 of the modulating substrate 11 with respect to the incident and outgoing portions 11a and 11b. The high-frequency interaction portion 11c has a thickness smaller than the those of the incident and outgoing portions 11a and 11b.

Abstract: 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.

Abstract: 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 substrate 5 made of an electro-optical material; a modulation electrode 2A, 3A, 2B provided on the substrate 5; and an optical waveguide 1c provided on the substrate 5. Light propagating through the optical waveguide 1c is modulated by applying a modulation voltage to the modulation electrode. At least a part of the modulation electrode includes a base 2a, 3a formed on the substrate 5 and a projection part 2b, 3b having a width narrower than that of the base.

Abstract: 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 electrode 3A, 3B and a ground electrode 2A, 2B provided on the substrate, an optical waveguide provided on the substrate. The signal electrode and the ground electrode each has an interaction section 2a, 2c, 3a, 3c and a feed-through section 2b, 2d, 3b, 3d. 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.

Abstract: An optical modulator 20 has an optical waveguide substrate 1 having a pair of principal surfaces 1a, 1c, a pair of side surfaces 1b and an incident face 1d and exit face 1e of light, the substrate being composed of a ferroelectric material; a channel optical waveguide 4 having at least a pair of branch sections 4b, a multiplexing section 6 of the branch sections and an exit section 4c provided on the downstream of the multiplexing section, the waveguide being formed on the principal surface 1a; a modulation electrode 2, 3 for applying a signal voltage for modulating light propagating in the branch sections; and a reflective groove 7 for reflecting leaked light of off-mode emitted from the multiplexing section 6 and emitting the light from the one principal surface 1a. 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.

Abstract: 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 columns 7A, 7B and 7C of at least first, second and third orders in distance with respect to said waveguide portion.

Abstract: 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 device 1A includes a substrate body 2 made of an electro-optical material, optical waveguide 6, and modulation electrodes 3, 4 and 5 for applying a voltage on the optical waveguide 6. The optical waveguide 6 includes first primary areas 6e and 6f, a first curved area 7A, first folding-back areas 6g and 6h provided between the first curved area 7A and a folding-back point 8, second primary areas 6m and 6n, a second curved area 7B, and second folding-back areas 6j and 6k provided between the second curved area 7B and the folding-back point 8. At least a part of the signal electrode is provided in a folding-back region extending from the first curved area 7A and the second curved area 7B to the folding-back point 8.

Abstract: A device 4 has a substrate 5, an optical waveguide 2 and modulation electrodes 1A, 1B, 1C. The substrate 5 is made of an electro-optic material and has a thickness of ?30 ?m at least in a region where the modulation electrode applies an electric field. The device has a ridge generated when the optical waveguide is formed, and the ridge has a height H (angstrom) and a width “W” (?m) whose product (H×W) is 7150 angstrom·?m or smaller to realize single mode propagation of light in the optical waveguide. The wave guide has branched parts in the region where the modulation electrode applied an electric field. The deviation of positions of peaks and bottoms in the extinction ratio curve can be reduced, by increasing the distance of the branched parts of the optical waveguide to ?46 ?m.

Abstract: The present invention provides a radio signal radiation system that alleviates the necessity of a highly specified pass band reception filter and a high performance/reliability amplifier. The radio signal radiation system includes an optical modulator; a light source for inputting an optical carrier wave into the optical modulator; a power source for applying a modulating signal having a frequency Fm on the optical modulator to superimpose a sideband wave onto the carrier wave, the modulating signal having an amplitude of N-times the drive voltage of the optical modulator; a light receiver to receive and convert the outgoing light into an electrical signal; and a radiating means for radiating a radio signal based on the electrical signal, wherein the sideband wave is superimposed at a position shifted by n×fm.

Abstract: 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 device includes a substrate body made of an electro-optical material, optical waveguide, and modulation electrodes for applying a voltage on the optical waveguide. The optical waveguide includes first primary areas, a first curved area, first folding-back areas provided between the first curved area and a folding-back point, second primary areas, a second curved area, and second folding-back areas provided between the second curved area 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 area and the second curved area to the folding-back point.