Abstract: An optical modulator includes a substrate on which an optical waveguide and a modulation electrode that modulates a light wave propagating through the optical waveguide are formed, and a case housing the substrate, the optical waveguide includes at least an optical branching part that branches one light wave into two light waves or an optical combining part that combines two light waves into one light wave, the modulation electrode has a signal electrode and a ground electrode, and a part of the signal electrode is disposed so as to cross the optical branching part or the optical combining part, and the optical modulator is provided with a suppressing unit that suppresses changes in an intensity ratio of the light waves branched at the optical branching part or an intensity ratio of the light waves combined at the optical combining part, by the signal electrode.

Abstract: A transmission line has a signal electrode formed on one surface of a flexible printed circuit, and a ground electrode formed on the other surface of the flexible printed circuit. A connection terminal has signal terminals formed on both the surfaces of the flexible printed circuit and electrically connected to each other through a via hole, and ground terminals formed on both the surfaces of the flexible printed circuit and electrically connected to each other through the via hole. The signal terminal on the surface, on which the ground electrode is formed, is formed such that at least a width in an end portion on the transmission line side is narrower than a width of a part of the signal terminal on the surface, on which the signal electrode is formed, to be at the same position when the flexible printed circuit is seen in a plan view.

Abstract: An optical waveguide device module includes an optical waveguide device and a connection substrate provided outside the optical waveguide device, and these are housed in a housing. The optical waveguide device has a control electrode including a signal electrode and ground electrodes disposed to interpose the signal electrode between the ground electrodes. A signal line, ground lines disposed so as to interpose the signal line between the ground lines, and a back surface ground electrode disposed on a surface of the connection substrate are provided on the connection substrate. The ground line and the back surface ground electrode are electrically connected through a via hole passing through the connection substrate. Electrical connection means for electrically connecting the ground line and the ground electrode is provided. A connection portion of the electrical connection means on the ground line side is in the vicinity of the via hole of the ground line.

Abstract: In a light modulation element that modulates light by controlling light waves that propagate through an optical waveguide, the realization of the additional broadening of the bandwidth by improving the degree of freedom in the design of the electrode is enabled. A light modulation element which includes optical waveguides formed on a substrate and a control electrode and modulates light by controlling light waves that propagate through the optical waveguide by conducting electricity in the control electrode, in which the control electrode includes radio frequency electrodes that configure a signal line through which radio frequency signals propagate and a bias electrode to which a bias voltage is applied, and the radio frequency electrode has a conductive layer made of copper or a copper alloy.

Abstract: An optical modulator includes a substrate, an optical waveguide, a control electrode applying a high frequency signal in order to modulate light waves propagating through the optical waveguide, and a relay substrate provided with a relay line to transfer the high frequency signal to the control electrode. The control electrode and the relay line together have a coplanar line structure inclusive of at least electrical connection portions of both the control electrode and the relay line. The control electrode includes an electrical connection portion and a routing portion positioned between the electrical connection portion and an active portion applying an electrical field to the optical waveguide. The routing portion has a coplanar line structure. A distance between ground electrodes sandwiching a signal electrode in the electrical connection portion of the control electrode is substantially equal to a distance between ground electrodes sandwiching a signal electrode of the routing portion.

Abstract: An optical modulator including an optical modulation element mounted inside a housing, in which at least a portion of an electric line is connected to an external circuit board through a flexible printed circuit, and which is disposed on the external circuit board. A recess portion that mounts the flexible printed circuit is formed on an outer bottom surface of the housing and at a part where the flexible printed circuit is connected, and a device for preventing a resonance mode is provided such that a resonance mode of a microwave and a millimeter wave or a parallel plate mode is prevented from being generated among a surface A of the recess portion facing the flexible printed circuit, an electric wiring part B provided on the flexible printed circuit overlapping the surface A when seen in a plan view, an electric wiring part C provided on the external circuit board overlapping the surface A when seen in a plan view.

Abstract: The objective of the present invention is to provide an optical modulator adapted for use with various modulating units and various modulation regions, and with which variability in optical losses is limited as far as possible.

Abstract: Provided is an optical waveguide device in which destabilization of a DC bias which is applied to an optical waveguide, due to a bias electrode picking up electric noise, is reduced and an operating characteristic is stable. An optical waveguide device includes: a substrate having an electro-optic effect; an optical waveguide formed on the substrate; a modulation electrode for applying an electric field corresponding to a modulation signal to the optical waveguide; and a bias electrode for applying an electric field corresponding to a DC bias to the optical waveguide, in which in order to reduce capture of electric noise by the bias electrode, with respect to at least a part of the bias electrode, a plurality of electrode portions (b11, b12) are formed in at least one (B1) of the pair of electrodes by folding back one electric line.

Abstract: An optical waveguide device module includes an optical waveguide device and a connection substrate provided outside the optical waveguide device, and these are housed in a housing. The optical waveguide device has a control electrode including a signal electrode and ground electrodes disposed to interpose the signal electrode between the ground electrodes. A signal line, ground lines disposed so as to interpose the signal line between the ground lines, and a back surface ground electrode disposed on a surface of the connection substrate are provided on the connection substrate. The ground line and the back surface ground electrode are electrically connected through a via hole passing through the connection substrate. Electrical connection means for electrically connecting the ground line and the ground electrode is provided. A connection portion of the electrical connection means on the ground line side is in the vicinity of the via hole of the ground line.

Abstract: An optical modulator includes a substrate, an optical waveguide, a control electrode applying a high frequency signal in order to modulate light waves propagating through the optical waveguide, and a relay substrate provided with a relay line to transfer the high frequency signal to the control electrode. The control electrode and the relay line together have a coplanar line structure inclusive of at least electrical connection portions of both the control electrode and the relay line. The control electrode includes an electrical connection portion and a routing portion positioned between the electrical connection portion and an active portion applying an electrical field to the optical waveguide. The routing portion has a coplanar line structure. A distance between ground electrodes sandwiching a signal electrode in the electrical connection portion of the control electrode is substantially equal to a distance between ground electrodes sandwiching a signal electrode of the routing portion.

Abstract: Provided is an optical modulator including: a relay substrate; a first transmission line that is provided on a flat surface of the relay substrate, and transmits an electrical signal along the flat surface; a second transmission line that is provided separately from the relay substrate, is electrically connected to the first transmission line, and transmits, to the first transmission line, the electrical signal that has been input from an outer side in a direction that is not included in the flat surface; a modulation unit that modulates an optical signal by using the electrical signal that is transmitted by the first transmission line and the second transmission line; and a shield that shields a radiation component of the electrical signal that is radiated from the second transmission line.

Abstract: An optical modulator including an optical modulation element mounted inside a housing, in which at least a portion of an electric line is connected to an external circuit board through a flexible printed circuit, and which is disposed on the external circuit board. A recess portion that mounts the flexible printed circuit is formed on an outer bottom surface of the housing and at a part where the flexible printed circuit is connected, and a device for preventing a resonance mode is provided such that a resonance mode of a microwave and a millimeter wave or a parallel plate mode is prevented from being generated among a surface A of the recess portion facing the flexible printed circuit, an electric wiring part B provided on the flexible printed circuit overlapping the surface A when seen in a plan view, an electric wiring part C provided on the external circuit board overlapping the surface A when seen in a plan view.

Abstract: A transmission line has a signal electrode formed on one surface of a flexible printed circuit, and a ground electrode formed on the other surface of the flexible printed circuit. A connection terminal has signal terminals formed on both the surfaces of the flexible printed circuit and electrically connected to each other through a via hole, and ground terminals formed on both the surfaces of the flexible printed circuit and electrically connected to each other through the via hole. The signal terminal on the surface, on which the ground electrode is formed, is formed such that at least a width in an end portion on the transmission line side is narrower than a width of a part of the signal terminal on the surface, on which the signal electrode is formed, to be at the same position when the flexible printed circuit is seen in a plan view.

Abstract: Provided is an optical modulator in which a phenomenon of a resonance mode or the like is prevented from being generated in a recess portion of a housing that mounts a flexible printed circuit and of which broadband characteristics are improved. There is provided an optical modulator in which an optical modulation element is mounted inside a housing, in which at least a portion of an electric line is connected to an external circuit board 7 through a flexible printed circuit 6, and which is disposed on the external circuit board.

Abstract: There is provided an optical control element module including: an optical control element having an optical waveguide and a control electrode on a substrate and disposed in a housing; an electrical connection part which is electrically connected to the control electrode, extends along a direction intersecting a plane on which the control electrode of the substrate is disposed, and is disposed in the housing; and a wiring substrate which has an input signal line electrically connected to the electrical connection part, at least a part of which is disposed outside the housing, in which impedance of the electrical connection part is set to be smaller than impedance of the input signal line.

Abstract: Provided is an optical modulator in which a phenomenon of a resonance mode or the like is prevented from being generated in a recess portion of a housing that mounts a flexible printed circuit and of which broadband characteristics are improved. There is provided an optical modulator in which an optical modulation element is mounted inside a housing, in which at least a portion of an electric line is connected to an external circuit board 7 through a flexible printed circuit 6, and which is disposed on the external circuit board.

Abstract: Provided is an optical waveguide device in which destabilization of a DC bias which is applied to an optical waveguide, due to a bias electrode picking up electric noise, is reduced and an operating characteristic is stable. An optical waveguide device includes: a substrate having an electro-optic effect; an optical waveguide formed on the substrate; a modulation electrode for applying an electric field corresponding to a modulation signal to the optical waveguide; and a bias electrode for applying an electric field corresponding to a DC bias to the optical waveguide, in which in order to reduce capture of electric noise by the bias electrode, with respect to at least a part of the bias electrode, a plurality of electrode portions (b11, b12) are formed in at least one (B1) of the pair of electrodes by folding back one electric line.

Abstract: Provided is an optical modulator in which low-voltage drive and a stable modulation characteristic are secured over a wide bandwidth.

Abstract: An optical element module includes an optical modulation element having first and second optical modulator units, a polarization combining means for combining two modulated lights which are emitted from the first and second optical modulator units, by making planes of polarization orthogonally cross each other; a housing which houses the optical modulation element and the polarization combining means; and a lens holder which holds a collimating lens which is disposed between the polarization combining means and an optical fiber, with the lens holder further holding the optical fiber. The optical element module is configured by joining the housing and the lens holder together by welding. In the lens holder, an outer diameter of a welding place is smaller than an outer diameter of a part which holds the collimating lens.

Abstract: There is provided an optical control element module including: an optical control element having an optical waveguide and a control electrode on a substrate and disposed in a housing; an electrical connection part which is electrically connected to the control electrode, extends along a direction intersecting a plane on which the control electrode of the substrate is disposed, and is disposed in the housing; and a wiring substrate which has an input signal line electrically connected to the electrical connection part, at least a part of which is disposed outside the housing, in which impedance of the electrical connection part is set to be smaller than impedance of the input signal line.