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: A small and inexpensive optical modulator having suppressed temperature drift and high reliability and an optical transmission device using the same are provided. The optical modulator includes an optical waveguide substrate where an optical waveguide is formed; a control electrode that is provided on the optical waveguide substrate and applies an electric field to the optical waveguide; and a relay substrate that is disposed in the vicinity of the optical waveguide substrate and includes electrical wirings that relay electrical signals from the outside to the control electrode. The control electrode includes a signal electrode. The optical modulator comprises terminating units that include terminal resistors that terminate the signal electrode. At least a part of the terminating units are provided on the relay substrate.

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 modulator and an optical transmission device using the same are provided. The optical modulator includes an optical waveguide substrate where an optical waveguide is formed; a light modulation element, provided in the optical waveguide substrate and including a modulation electrode applying an electric field corresponding to a modulation signal to the optical waveguide; a terminal substrate, disposed near the light modulation element and including terminal resistors that terminate the modulation signal, wherein the optical waveguide substrate, the light modulation element and the terminal substrate are accommodated in a housing; and a heat dissipation auxiliary element, provided between the terminal resistors and the housing. A distance b between the terminal resistors and the heat dissipation element is set to be shorter than a distance a from the terminal resistors to an end on the side of the optical waveguide substrate of the terminal substrate.

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: In an optical modulator including an FPC for performing electrical connection with an external circuit substrate, to maintain high light transmission quality by appropriately driving the optical modulator even when the reflection of a radio frequency signal occurs in a connection portion between the FPC and the main body of the optical modulator. Provided is an optical modulator including a flexible printed circuit for performing electrical connection with a circuit substrate, in which the flexible printed circuit includes at least one wire pattern for propagating a radio frequency signal, and the wire pattern includes at least one radio frequency attenuation portion for attenuating power of the radio frequency signal by a predetermined amount.

Abstract: An optical modulator with FPC and optical transmission device using the same are provided. This optical modulator includes a flexible printed circuit which electrically connects the optical modulator to a circuit board. The flexible printed circuit has a substantially quadrilateral shape. A pad is formed on the flexible printed circuit along one side of the substantially quadrilateral shape so as to be electrically connected to the circuit board. In order to release the mechanical stress applied onto the side or the end portion of the flexible printed circuit and/or to prevent propagation of distortion generated in the side or the end portion, the flexible printed circuit has: a cutout or a notch provided in a direction from a part of at least one side toward the inside of the flexible printed circuit; and/or a curved portion connecting at least two adjacent sides.

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: Provided is an optical modulator capable of effectively dispersing and releasing heat generated by termination resistors, improving the reliability of a termination substrate including the termination resistors, and reducing influence of heat on an optical waveguide.

Abstract: An optical modulator using an optical modulation element in which an optical waveguide and a plurality of electrodes for controlling light waves propagating through the optical waveguide are formed on a substrate, in which at least one stress relieving structure is provided on an upper surface of the electrode opposite to a surface of the substrate in order to relieve stress generated due to pressure applied at the time of wire-bonding of a metal wire.

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: To perform a stable bias control by improving detection accuracy of intensity of an dither signal component, which is detected by a photo detector, in an optical modulator including a bias electrode to which a dither signal is applied, and a photo detector that monitors an optical signal propagating through the inside of an optical waveguide in the same substrate. The optical modulator includes: a substrate having a piezoelectric effect (102); an optical waveguide (116a or the like) that is formed on the substrate; a bias electrode (158a or the like) that controls an optical wave that propagates through the optical waveguide; and a photo detector (168a or the like) that is formed on the substrate, and monitors an optical signal that propagates along the optical waveguide.

Abstract: An optical modulator and an optical transmission device using the same are provided. The optical modulator includes an optical waveguide substrate where an optical waveguide is formed; a light modulation element, provided in the optical waveguide substrate and including a modulation electrode applying an electric field corresponding to a modulation signal to the optical waveguide; a terminal substrate, disposed near the light modulation element and including terminal resistors that terminate the modulation signal, wherein the optical waveguide substrate, the light modulation element and the terminal substrate are accommodated in a housing; and a heat dissipation auxiliary element, provided between the terminal resistors and the housing. A distance b between the terminal resistors and the heat dissipation element is set to be shorter than a distance a from the terminal resistors to an end on the side of the optical waveguide substrate of the terminal substrate.

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: A small and inexpensive optical modulator having suppressed temperature drift and high reliability and an optical transmission device using the same are provided. The optical modulator includes an optical waveguide substrate where an optical waveguide is formed; a control electrode that is provided on the optical waveguide substrate and applies an electric field to the optical waveguide; and a relay substrate that is disposed in the vicinity of the optical waveguide substrate and includes electrical wirings that relay electrical signals from the outside to the control electrode. The control electrode includes a signal electrode. The optical modulator comprises terminating units that include terminal resistors that terminate the signal electrode. At least a part of the terminating units are provided on the relay substrate.

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: An optical modulator with FPC and optical transmission device using the same are provided. This optical modulator includes a flexible printed circuit which electrically connects the optical modulator to a circuit board. The flexible printed circuit has a substantially quadrilateral shape. A pad is formed on the flexible printed circuit along one side of the substantially quadrilateral shape so as to be electrically connected to the circuit board. In order to release the mechanical stress applied onto the side or the end portion of the flexible printed circuit and/or to prevent propagation of distortion generated in the side or the end portion, the flexible printed circuit has: a cutout or a notch provided in a direction from a part of at least one side toward the inside of the flexible printed circuit; and/or a curved portion connecting at least two adjacent sides.

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: In an optical modulator including an FPC for performing electrical connection with an external circuit substrate, to maintain high light transmission quality by appropriately driving the optical modulator even when the reflection of a radio frequency signal occurs in a connection portion between the FPC and the main body of the optical modulator. Provided is an optical modulator including a flexible printed circuit for performing electrical connection with a circuit substrate, in which the flexible printed circuit includes at least one wire pattern for propagating a radio frequency signal, and the wire pattern includes at least one radio frequency attenuation portion for attenuating power of the radio frequency signal by a predetermined amount.

Abstract: To perform a stable bias control by improving detection accuracy of intensity of an dither signal component, which is detected by a photo detector, in an optical modulator including a bias electrode to which a dither signal is applied, and a photo detector that monitors an optical signal propagating through the inside of an optical waveguide in the same substrate. The optical modulator includes: a substrate having a piezoelectric effect (102); an optical waveguide (116a or the like) that is formed on the substrate; a bias electrode (158a or the like) that controls an optical wave that propagates through the optical waveguide; and a photo detector (168a or the like) that is formed on the substrate, and monitors an optical signal that propagates along the optical waveguide.