Patent application number | Description | Published |
20100104237 | WAVEGUIDE-TYPE OPTICAL INTERFEROMETER - In an optical interferometer, polarization dependence attributable to the optical path difference has conventionally been eliminated by inserting a half-wave plate at the center of the interferometer. However, light induced by polarization coupling produced in directional couplers used in the optical interferometer causes interference having different interference conditions from those of the normal light. Polarization rotators that effect any one of 90° rotation and −90° rotation of all states of polarization of incoming light are inserted in the optical interferometer, and thereby the interference conditions of light induced by polarization coupling are made the same as those of the normal light. Each of the polarization rotators is implemented by using two half-wave plates and by varying an angle of combination of these half-wave plates. Alternatively, each of the polarization rotators is implemented through a combination of one half-wave plate and a waveguide having birefringence properties. | 04-29-2010 |
20100119189 | OPTICAL DELAY LINE INTERFEROMETER - A demodulator is provided for a multilevel differential phase shift keyed signal, capable of eliminating polarization dependence due to birefringence and polarization coupling-induced light resulting from a waveguide structure, and also, polarization dependence due to dynamic birefringence produced at the time of driving a variable phase adjuster. The demodulator is configured of an optical delay line interferometer of a waveguide interference type. The S/N ratio of a demodulated signal in the demodulator formed by the optical delay line interferometer can be also improved. Further, both the polarization dependence and the temperature dependence of the optical delay line interferometer can be reduced. The disposition of a polarization converter and groves filled with a temperature compensation material makes it possible to provide a circuit configuration suitable for eliminating the polarization dependence and the temperature dependence of the optical delay line interferometer. | 05-13-2010 |
20110268447 | Optical Wavelength Multiplexing/Demultiplexing Circuit, Optical Module Using Optical Wavelength Multiplexing/Demultiplexing Circuit, and Communication System - When a conventional synchronized AWG is employed to extend a transmission passband, an increase in loss near the optical center frequency can not be avoided. Because of passband width limit, a problem has existed in that the synchronized AWG could not be applied for a large, complicated communication system wherein a signal light passes a number of points. Therefore, an optical wavelength multiplexing/demultiplexing circuit of the present invention is a synchronized AWG, which includes an optical splitter arranged in an interference circuit that is connected on the side of one slab waveguide. The splitting ratio of the optical splitter varies, depending on the optical frequency, and the value becomes minimum near the optical center frequency of the synchronized AWG. The optical splitter is operated so that the splitting ratio is comparatively great at optical frequencies distant from the optical center frequency. | 11-03-2011 |
20120025669 | DRIVE APPARATUS - A drive apparatus according to an embodiment includes: a movable unit configured to include a first sliding surface, and slide along the first sliding surface; a vibration generating unit configured to generate vibrations; a vibration transmitting unit configured to include a second sliding surface in contact with the first sliding surface of the movable unit, and transmit the vibrations generated by the vibration generating unit to the movable unit via the first and second sliding surfaces; a pre-pressure applying unit configured to apply pre-pressure to the movable unit via the vibration transmitting unit; and a driving force generating unit configure to generate a driving force for driving the movable unit in a predetermined direction, the driving force being greater than a friction force between the first sliding surface and the second sliding surface when the vibrations are being transmitted to the vibration transmitting unit, the driving force being smaller than the friction force when the vibrations are not being transmitted to the vibration transmitting unit. | 02-02-2012 |
20120082414 | OPTICAL 90-DEGREE HYBRID CIRCUIT - An optical 90-degree hybrid circuit includes: first and second optical splitters for receiving and splitting a first and second light beam into two, respectively; a first optical coupler for generating an interfering light beam by multiplexing one of the light beams split by the first optical splitter and the second optical splitter; and a second optical coupler for generating an interfering light beam by multiplexing another one of the light beams split by the first optical splitter and the second optical splitter. The first optical splitter includes an optical coupler configured to output two light beams having equal phases, and the second optical splitter includes an optical coupler configured to output two light beams having a phase difference of 90 degrees. | 04-05-2012 |
20120093457 | OPTICAL 90-DEGREE HYBRID CIRCUIT - An optical 90-degree hybrid circuit includes a first demultiplexing optical coupler having two or more first input ports and two or more first output ports, a second demultiplexing optical coupler having two or more second input ports and two or more second output ports, two first arm waveguides connected to the first output ports, two second arm waveguides connected to the second output ports, a 90-degree phase shift section installed in one of the four arm waveguides, a first optical coupler and a second optical coupler connected to the first arm waveguides and the second arm waveguides, a first optical waveguide for connecting an optical splitter and the first input ports, and a second optical waveguide for connecting the optical splitter and the second input ports, wherein an optical length of the first optical waveguide is different from that of the second optical waveguide. | 04-19-2012 |
20120141067 | OPTICAL 90-DEGREE HYBRID CIRCUIT - The present invention provides an optical 90-degree hybrid circuit for reducing wavelength dependency of an IQ phase difference. An optical 90-degree hybrid circuit according to the present invention comprises a first demultiplexing optical coupler including a first and second input port, a second demultiplexing optical coupler including a third and fourth input port, first and second arm waveguides connected to the first and second input port, each having the same length, a third and fourth arm waveguides connected to the third and fourth input port, each having the same length, a 90-degree phase shift section installed in one of the first to fourth arm waveguides, a first optical coupler connected to the first and third arm waveguide, and a second optical coupler connected to the second and fourth arm waveguide, the light is inputted into the first and fourth input port or into the second and third input port. | 06-07-2012 |
20140117793 | TRANSVERSE FLUX MOTOR - A transverse flux motor of an aspect of embodiments includes a rotor having an outer peripheral surface, an annular armature coil wound around a rotational axis of the rotor, a stator core including a pair of magnetic pole portions along an axial direction of the rotational axis, each magnetic pole portion facing the outer peripheral surface of the rotor across a gap and a supporting member containing the armature coil, and having a plurality of protruding portions protruding in the axial direction and provided around the rotational axis, wherein the adjacent two protruding portions around the rotational axis support at least part of the magnetic pole portions between the adjacent two protruding portions. | 05-01-2014 |