Abstract: To suppress peeling-off or cracks of a solder-fixing portion, which are caused by vibration during transportation or operation, in an optical modulator with FPC, thereby suppressing deterioration of radio-frequency characteristics of a signal path in an effective manner at low cost. An optical modulator 100 includes a flexible printed circuit (106) that performs electrical connection with a circuit substrate. The flexible printed circuit has a substantially quadrilateral shape. In the flexible printed circuit, a pad (210 and the like), which is electrically connected to the circuit substrate, is provided along one side of the substantial quadrilateral. In addition, in the flexible printed circuit, signal patterns (220 and the like), which are connected to signal lead pins (120 and the like) for signal transmission which is provided in the optical modulator, are provided in another side opposite to the one side.

Abstract: An optical modulation element configured by forming an optical waveguide on an optical element substrate and a polarization-combining part that combines light waves modulated in the optical modulation element are disposed in a housing. A plurality of lead pins are fixed to a side wall of the housing. Each of the plurality of lead pins has a protrusion portion protruding into an internal space of the housing and is electrically connected to the optical modulation element by bonding a wire to the protrusion portion. A loop shape of a wire that is bonded and connected to at least part of the lead pins among the plurality of lead pins is different from a loop shape of a wire that is bonded and connected to other lead pins.

Abstract: An optical modulator including a flexible printed circuit performing an electrical connection with an external circuit substrate, in which the flexible printed circuit includes a plurality of first pads and the like provided on one surface of the flexible printed circuit along one side of the flexible printed circuit, a plurality of second pads and the like provided on the other surface of the flexible printed circuit at locations that respectively correspond to the plurality of first pads, and a plurality of metal films and the like provided at locations that respectively correspond to the first pads on a side surface of the flexible printed circuit along the one side of the flexible printed circuit.

Abstract: A waveguide optical element which includes a plurality of optical waveguides provided on a substrate having an electro-optic effect includes: a plurality of signal electrodes controlling light waves propagating through the optical waveguides; and a plurality of ground electrodes provided so as to interpose each of the signal electrodes therebetween, in which at least one of the ground electrodes includes a first layer and a second layer formed on the first layer, the second layer is formed such that a distance between the second layer and the signal electrode adjacent to the second layer is larger than a distance between the first layer and said signal electrode adjacent to said second layer, and a thickness of the ground electrode which includes the first layer and the second layer is 25 ?m or more.

Abstract: An optical modulator includes an optical modulation element that is accommodated in a housing. A plurality of lead pins, which are electrically connected to the optical modulation element through wire bonding, are fixed to a lateral wall of the housing. Each of the plurality of lead pins includes a portion that protrudes into an inner space (inner surface side) of the housing. A resonance suppressing structure (for example, a concave portion), which is configured to suppress resonance between the lead pins, is provided in a lateral wall portion to which the plurality of lead pins are fixed.

Abstract: An optical modulator includes an optical modulation element including a plurality of signal electrodes and the like, a plurality of lead pins and the like for inputting radio frequency signals, and a relay substrate in which conductor patterns and the like that electrically connect the lead pins with the signal electrodes respectively are formed, the relay substrate is disposed so that a propagation direction of the radio frequency signals that have propagated through the lead pins is bent and guided to the conductor patterns, and the relay substrate is constituted so that widths of gaps between the plurality of conductor patterns in the optical modulator-side edge of the relay substrate is smaller than, preferably smaller than 50% of widths of gaps between the plurality of conductor patterns in the lead pin-side edge.

Abstract: An optical modulator includes: an optical modulation element which includes signal electrodes; lead pins; and a relay substrate in which a conductor pattern which electrically connects each of the lead pins and each of the signal electrodes to each other are formed, and the optical modulator is configured such that the amount of radiation of a high frequency at a connection portion between the conductor pattern and the signal electrode is increased compared to a portion other than the connection portion.

Abstract: A substrate (102) having a piezoelectric effect, optical waveguides (138a, 140a, 138b, 140b, and the like) formed on the substrate, and a plurality of bias electrodes (152a, 152b, and the like) that control an optical wave (s) which propagate through the optical waveguides are provided, and the bias electrodes are constituted and/or disposed such that an electrical signal applied to one of the bias electrodes is prevented from being received by another one of the bias electrodes through a surface acoustic wave.

Abstract: Provided is an optical modulator in which an optical modulation element is accommodated in a housing. A plurality of lead pins, which are electrically connected to the optical modulation element through wire bonding, are fixed to the housing in a manner of protruding at least a part of each of the plurality of lead pins into the housing. In the plurality of lead pins, lengths of the lead pins are set to be different from each other so that a natural frequency of at least partial lead pins is different from a natural frequency of the other lead pins.

Abstract: An optical modulator includes: an optical modulation element which is accommodated in a housing and has a signal electrode; a lead pin for inputting a high-frequency signal; a relay substrate in which a conductor pattern which electrically connects the lead pin and the signal electrode is formed; and a conductive extension portion which extends along a length direction of the lead pin in a range which includes at least a position of a connection portion between the lead pin and the conductor pattern, in which the extension portion is electrically connected to the housing.

Abstract: A substrate (102) having a piezoelectric effect, optical waveguide (138a, 140a, 138b, 140b, and the like) formed on the substrate, and a plurality of bias electrodes (152a, 152b, and the like) that control an optical wave (s) which propagate through the optical waveguides are provided, and the bias electrodes are constituted and/or disposed such that an electrical signal applied to one of the bias electrodes is prevented from being received by another one of the bias electrodes through a surface acoustic wave.

Abstract: An optical modulator includes an optical modulation element (102) including a plurality of signal electrodes (112a and the like), a plurality of lead pins (116a and the like) for inputting high frequency signals, and a relay substrate (118) in which conductor patterns (202a and the like) that electrically connect the lead pins and the signal electrodes are formed, and at least one of the conductor patterns in the optical modulator is constituted so that at least one resonant frequency of the at least one of the conductor patterns is different from at least one resonant frequency of at least one of the other conductor patterns.

Abstract: An optical modulator includes an optical modulation element including a plurality of signal electrodes and the like, a plurality of lead pins and the like for inputting radio frequency signals, and a relay substrate in which conductor patterns and the like that electrically connect the lead pins with the signal electrodes respectively are formed, the relay substrate is disposed so that a propagation direction of the radio frequency signals that have propagated through the lead pins is bent and guided to the conductor patterns, and the relay substrate is constituted so that widths of gaps between the plurality of conductor patterns in the optical modulator-side edge of the relay substrate is smaller than, preferably smaller than 50% of widths of gaps between the plurality of conductor patterns in the lead pin-side edge.

Abstract: An optical modulator including a flexible printed circuit performing an electrical connection with an external circuit substrate, in which the flexible printed circuit includes a plurality of first pads and the like provided on one surface of the flexible printed circuit along one side of the flexible printed circuit, a plurality of second pads and the like provided on the other surface of the flexible printed circuit at locations that respectively correspond to the plurality of first pads, and a plurality of metal films and the like provided at locations that respectively correspond to the first pads on a side surface of the flexible printed circuit along the one side of the flexible printed circuit.

Abstract: A substrate (102) having a piezoelectric effect, optical waveguide (138a, 140a, 138b, 140b, and the like) formed on the substrate, and a plurality of bias electrodes (152a, 152b, and the like) that control an optical wave (s) which propagate through the optical waveguides are provided, and the bias electrodes are constituted and/or disposed such that an electrical signal applied to one of the bias electrodes is prevented from being received by another one of the bias electrodes through a surface acoustic wave.

Abstract: In order to provide an optical modulator capable of suppressing generation of mode mismatching light in the Y-multiplexer in the MZ-type waveguide or mixing of the mode mismatching light with the radiation-mode light or the output light, and separately extracting output light and radiation-mode light, there is provided an optical modulator having a Mach-Zehnder type waveguide on a surface of a dielectric substrate, wherein a waveguide after multiplexing in a Y-multiplexer in an output side of the Mach-Zehnder type waveguide is a multiple mode waveguide 2, a subsidiary output waveguide as a high-order mode waveguide 2 is connected to a portion where the multiple mode waveguide is changed to a main output waveguide 3 as a single mode waveguide, and the multiple mode waveguide 2 has a length equal to or longer than 150 ?m.

Abstract: An object of the present invention is to provide a manufacturing method of an optical waveguide element whose DC drift is suppressed, and to provide a manufacturing method of an optical waveguide element, capable of adjusting DC drift in the middle of manufacturing processes so as to improve a fabrication yield. The method of manufacturing an optical waveguide element comprises a step of forming an optical waveguide in a substrate having an electro-optic effect, a step of forming a buffer layer, and a step of forming an electrode, in which one stage or a plurality of stages of an interface diffusion layer heat adjustment step (S1, S2) for adjusting a concentration distribution of a specific substance in the buffer layer by heating is included after the buffer layer is formed.

Abstract: An object of the present invention is to provide a manufacturing method of an optical waveguide element whose DC drift is suppressed, and to provide a manufacturing method of an optical waveguide element, capable of adjusting DC drift in the middle of manufacturing processes so as to improve a fabrication yield. The method of manufacturing an optical waveguide element comprises a step of forming an optical waveguide in a substrate having an electro-optic effect, a step of forming a buffer layer, and a step of forming an electrode, in which one stage or a plurality of stages of an interface diffusion layer heat adjustment step (S1, S2) for adjusting a concentration distribution of a specific substance in the buffer layer by heating is included after the buffer layer is formed.

Abstract: Provided is an optical waveguide element module which suppresses reflection of a modulation signal and attenuation of a modulation signal, even when an impedance of a modulation electrode of an optical waveguide element and an impedance of a transmission line for inputting the modulation signal from the external of the optical waveguide element are different from each other. The optical waveguide element module is provided with an optical waveguide element, which has a substrate (1) composed of a material having electro-optical effects, an optical waveguide (2) formed on the substrate, and a modulation electrode (3) which modules optical waves propagating in the optical waveguide; a connector (8), wherein an external signal line which inputs the modulation signal to the modulation electrode is connected to the modulation electrode; and a relay line which connects the connector and the modulation electrode and is formed on a relay substrate (7).

Abstract: Disclosed is an optical waveguide element module in which a filter circuit including a capacitor is provided on a line through which a modulation signal is input to a modulating electrode of an optical waveguide element. The module is capable of preventing the deterioration of an electric signal in the filter circuit or the occurrence of a resonance phenomenon within the frequency range used and obtaining flat electrical/optical response frequency characteristics in a wide band of more than several tens of gigahertz. The capacitor is a single-layer capacitor and the relative permittivity of a dielectric in the capacitor is equal to or less than 1000.