Abstract: A configuration of acousto-optical tunable filters (AOTF) having stable output characteristics so that the output does not significantly vary with time. The configuration includes a plurality of AOTFs cascaded together. Each AOTF generates a surface acoustic wave in an optical waveguide in accordance with RF signals applied to the AOTF. A phase of a beat generated by the RF signals applied to one of the plurality of AOTFs is different from a phase of a beat generated by the RF signals applied to a different AOTF of the plurality of AOTFs.

Abstract: The present invention relates to an optical modulator allowing appropriate interaction between signal electrodes and an optical waveguide, only by matching phases at input ends of the signal electrodes. The optical modulator includes an optical waveguide with its center part branched into two at two Y-branch waveguides, forming first and second waveguide arms, a first signal electrode transmitting a first electric signal interacting with first light propagating through the first waveguide arm in a predetermined manner, a second signal electrode transmitting a second electric signal interacting with second light propagating through the second waveguide arm in a predetermined manner, and earthed electrodes, and can match the interacting timing between the first electric signal and the first light to the interacting timing between the second electric signal and the second light, at a first input end supplying the first electric signal and a second input end supplying the second electric signal.

Abstract: The present disclosure relates to a device for modulating light emitted by a laser, including an optical substrate that has an electro-optical effect, at least one optical waveguide formed near a front face of the optical substrate, a first electrode that is formed with a conductive transparent film so that a part of the optical waveguide may be covered and is used for applying an electric field to the optical waveguide, a second electrode that is paired with the first electrode and is used for applying an electric field to the optical waveguide, and a third electrode that is formed with a metal film in a position that is shifted from a position just above the optical waveguide and is electrically connected with the first electrode.

Abstract: The present invention relates to an optical modulator allowing appropriate interaction between signal electrodes and an optical waveguide, only by matching phases at input ends of the signal electrodes. The optical modulator includes an optical waveguide with its center part branched into two at two Y-branch waveguides, forming first and second waveguide arms, a first signal electrode transmitting a first electric signal interacting with first light propagating through the first waveguide arm in a predetermined manner, a second signal electrode transmitting a second electric signal interacting with second light propagating through the second waveguide arm in a predetermined manner, and earthed electrodes, and can match the interacting timing between the first electric signal and the first light to the interacting timing between the second electric signal and the second light, at a first input end supplying the first electric signal and a second input end supplying the second electric signal.

Abstract: The present invention relates to an optical modulator allowing appropriate interaction between signal electrodes and an optical waveguide, only by matching phases at input ends of the signal electrodes. The optical modulator includes an optical waveguide with its center part branched into two at two Y-branch waveguides, forming first and second waveguide arms, a first signal electrode transmitting a first electric signal interacting with first light propagating through the first waveguide arm in a predetermined manner, a second signal electrode transmitting a second electric signal interacting with second light propagating through the second waveguide arm in a predetermined manner, and earthed electrodes, and can match the interacting timing between the first electric signal and the first light to the interacting timing between the second electric signal and the second light, at a first input end supplying the first electric signal and a second input end supplying the second electric signal.

Abstract: A transfer guide is provided which includes a guide member for guiding paper to a transfer point and a paper holding member using an electrically conductive member attached to the guide member by means of a spring member and disposed in the vicinity of a surface of a photosensitive drum, such that the gap becomes narrow for thin paper and the gap widens for thick paper in correspondence with the ream weight of the paper.

Abstract: In the case in which independent driving voltages are applied to electrodes that are provided in waveguides #1 and #2 of a Mach-Zehnder optical modulator, light passing through the waveguide #1 and light passing through the waveguide #2 undergo the same amount of phase modulation of opposite signs (positive and negative) while a driving voltage E1 is applied. Similarly, the Mach-Zehnder optical modulator is configured so that when a driving voltage E2 is applied, phase modulation provided to the light passing through the waveguide #1 and phase modulation provided to the light passing through the waveguide #2 are offset after these lights are coupled. With this configuration, the amount of phase modulation provided by the Mach-Zehnder optical modulator is always kept at “0”, resulting in that chirping, which is defined as the differentiation of a phase modulation amount with respect to time, does not occur.

Abstract: In the case in which independent driving voltages are applied to electrodes that are provided in waveguides #1 and #2 of a Mach-Zehnder optical modulator, light passing through the waveguide #1 and light passing through the waveguide #2 undergo the same amount of phase modulation of opposite signs (positive and negative) while a driving voltage E1 is applied. Similarly, the Mach-Zehnder optical modulator is configured so that when a driving voltage E2 is applied, phase modulation provided to the light passing through the waveguide #1 and phase modulation provided to the light passing through the waveguide #2 are offset after these lights are coupled. With this configuration, the amount of phase modulation provided by the Mach-Zehnder optical modulator is always kept at “0”, resulting in that chirping, which is defined as the differentiation of a phase modulation amount with respect to time, does not occur.

Abstract: The present disclosure relates to a device for modulating light emitted by a laser, including an optical substrate that has an electro-optical effect, at least one optical waveguide formed near a front face of the optical substrate, a first electrode that is formed with a conductive transparent film so that a part of the optical waveguide may be covered and is used for applying an electric field to the optical waveguide, a second electrode that is paired with the first electrode and is used for applying an electric field to the optical waveguide, and a third electrode that is formed with a metal film in a position that is shifted from a position just above the optical waveguide and is electrically connected with the first electrode.

Abstract: The present invention relates to an optical modulator allowing appropriate interaction between signal electrodes and an optical waveguide, only by matching phases at input ends of the signal electrodes. The optical modulator includes an optical waveguide with its center part branched into two at two Y-branch waveguides, forming first and second waveguide arms, a first signal electrode transmitting a first electric signal interacting with first light propagating through the first waveguide arm in a predetermined manner, a second signal electrode transmitting a second electric signal interacting with second light propagating through the second waveguide arm in a predetermined manner, and earthed electrodes, and can match the interacting timing between the first electric signal and the first light to the interacting timing between the second electric signal and the second light, at a first input end supplying the first electric signal and a second input end supplying the second electric signal.

Abstract: An optical device has a substrate, a polarization beam splitter, first and second pairs of optical waveguides, a transducer and a thin film. The polarization beam splitter is formed on the substrate and has input and output sides. The first and second pairs of optical waveguides are formed on the substrate to guide polarized optical signals. The first pair of optical waveguides meets at the input side of the polarization beam splitter, and the second pair of optical waveguides meets at the output side of the polarization beam splitter. The transducer is formed of a comb-tooth electrode on the substrate to excite a surface acoustic wave on the substrate and rotate the polarization of the optical signal. The thin film covers a portion of each waveguide of either the first or second pairs of optical waveguides. The thin film may be formed of silicon dioxide or indium dioxide, either with a metal oxide optionally added thereto. The speed of sound in the thin film is less than that in the substrate.

Abstract: An acousto-optical device includes a light waveguide path formed on an acousto-optical substrate, a transducer which crosses the light waveguide path and propagates a surface acoustic wave along the light waveguide path, and a buffer layer provided so that finger electrodes of the transducer are spaced apart from the light waveguide path in crossing portions in which the finger electrodes cross the light waveguide path. The finger electrodes have other portions which directly contact the substrate.

Abstract: An acousto-optical device includes a light waveguide path formed on an acousto-optical substrate, a transducer which crosses the light waveguide path and propagates a surface acoustic wave along the light waveguide path, and a buffer layer provided so that finger electrodes of the transducer are spaced apart from the light waveguide path in crossing portions in which the finger electrodes cross the light waveguide path. The finger electrodes have other portions which directly contact the substrate.

Abstract: The present invention relates to an optical device to be used for, for example, terminal apparatus or repeating installations of optical communication systems. In order to reduce an inter-polarization error of an optical signal taking place at input of an optical signal with a high bit rate to enhance the optical signal communication accuracy, the optical device is constructed such that optical waveguides are formed on substrates each having a double refraction, and the two inter-polarization effective optical path lengths for the optical signal are made to be equal to each other at the optical signal propagation in the optical waveguides.

Abstract: A transfer guide is provided which includes a guide member for guiding paper to a transfer point and a paper holding member using an electrically conductive member attached to the guide member by means of a spring member and disposed in the vicinity of a surface of a photosensitive drum, such that the gap becomes narrow for thin paper and the gap widens for thick paper in correspondence with the ream weight of the paper.

Abstract: In an electrophotographic printing apparatus, when the conveying speed of the timing roller (1a, 1b) is Vt, the conveying speed of the register roller (2a, 2b) is Vr, the peripheral speed of the photoreceptor drum (3) is V0, and the conveying speed of the conveying apparatus (5) is Vf, each speed is set to satisfy the relationship of Vf>V0≧Vr>Vt, and when a sheet deflection amount formed when the sheet comes into contact with the register roller, is &dgr;r, the sheet deflection amount at the photoreceptor drum entry section is &dgr;0, and the sheet length is Lp, each value is regulated so that the relationships of &dgr;r≧Lp ((Vr−Vt)/Vt) and &dgr;0≧Lp ((Vf−V0)/V0) are satisfied.

Abstract: An optical waveguide device having a folded waveguide structure on a semiconductor substrate. The optical waveguide device includes first and second single mode optical waveguides formed on a semiconductor substrate. The first and second optical waveguides merge together into a merging optical waveguide. A reflector is positioned so that light travelling through the first optical waveguide into the merging optical waveguide is reflected by the reflector to travel through the second optical waveguide. A total reflection complementary angle for the light traveling through the first optical waveguide is &thgr;c, and a branch angle &thgr;b of the first and second optical waveguides is less than or equal to 0.55&thgr;c.

Abstract: A compact optical device operating as a WDM (wavelength division multiplexing) filter is provided. The optical device includes a slab optical waveguide having first and second end faces opposed to each other, a plurality of first optical waveguides connected to the first end face of the slab optical waveguide, and a plurality of second optical waveguides connected to the second end face of the slab optical waveguide. Each of the second optical waveguides includes a first cavity connected to the slab optical waveguide and a second cavity acutely connected through a first reflecting surface to the first cavity. The second cavity is terminated by a second reflecting surface. Each second cavity is so configured as to be folded back to the corresponding first cavity, so that the optical device can be made compact in setting a required optical path difference between the second optical waveguides. This optical device can be used as an optical multiplexer or an optical demultiplexer in a system adopting WDM.

Abstract: An optical device and manufacturing method therefor relate to a slab optical waveguide, a first optical waveguide, a plurality of second optical waveguides and a reflector. The slab optical waveguide has first and second ends. The first optical waveguide is optically connected to the first end of the slab optical waveguide. The plurality of second optical waveguides each have first and second guide bars with the first guide bars being optically connected to the second end of the slab optical waveguide and the second guide bars being optically connected to the first guide bars. The second guide bars may have a width greater than that of the first guide bars. The reflector is optically connected to each of the second guide bars of the second optical waveguides. The reflector may be formed on an end face on each of the second guide bars substantially perpendicular to an optical axis of the respective first guide bars.

Abstract: An optical modulator suitable for use in, for example, a terminal apparatus in an optical communication system when an optical signal is modulated has a power splitting unit for splitting a power of an incident light into two split lights, a first intensity modulating unit for performing an intensity modulation on one of the split lights split by the power splitting unit and outputting an intensity-modulated optical signal containing a direct current component, an optical phase shifting unit for performing a phase shift on the other of the split lights split by the power splitting unit such that the light has a phase opposite to that of the intensity-modulated optical signal, and a direct current component suppressing unit for making the intensity-modulated optical signal and the light subjected to the phase shift interfere with each other to suppress the direct current component contained in the intensity-modulated optical signal and outputting the intensity-modulated optical signal, thereby obtaining the mo