Abstract: An optical multiplexing/demultiplexing apparatus in which a plurality of optical multiplexing/demultiplexing units operating in different wavelength bands are connected hierarchically. Each of the plurality of optical multiplexing/demultiplexing units includes an input waveguide for receiving wavelength multiplexed optical waves, a filter for separating the wavelength multiplexed optical wave from the input waveguide into a first optical wave in a corresponding operating wavelength band and a second optical wave in the other wavelength bands. Each of the multiplexing/demultiplexing units also includes an AWG optical multiplexer/demultiplexer for separating the first optical wave from the filter into individual optical waves each of a single wavelength, and a branch waveguide for directing the second optical waves from the filter to an input waveguide of a succeeding optical multiplexing/demultiplexing unit.

Abstract: The object of the present invention is to provide a full-mesh optical wavelength division multiplexing transmission network device which is capable of exhibiting excellent communication quality and being mass produced, by reducing the accumulation number of coherent crosstalk lights, without any modification of constituent components constituting the conventional one. In the full-mesh optical wavelength division multiplexing transmission network device, provided is an N×N wavelength multi/demultiplexer having a periodic wavelength demultiplexing property in input/output combination, which performs input/output from/to first and second I/O port groups for optical signals and allows lightwaves traveling in opposite directions not to interfere with each other within the circut, thus reducing the accumulation number of coherent crosstalk lights in WDM wavelength lights and improving S/N of a received light.

Abstract: An optical multiplexing/demultiplexing apparatus in which a plurality of optical multiplexing/demultiplexing units which are different from one another in operating wavelength band are connected hierarchically. Each of the optical multiplexing/demultiplexing units comprises an input waveguide for receiving a wavelength multiplexed optical waves, a filter for separating the wavelength multiplexed optical wave from the input waveguide into a first optical wave in the corresponding operating wavelength band and a second optical wave in the other wavelength bands, an AWG optical multiplexer/demultiplexer for separating the first optical wave from the filter into individual optical waves each of a single wavelength, and a branch waveguide for directing the second optical waves from the filter to the input waveguide of a succeeding optical multiplexing/demultiplexing unit.

Abstract: In an optical module having a silicon substrate, a plurality of optical semiconductor devices and optical waveguides for performing transmission of optical signals by the semiconductor devices integrated on the silicon substrate, the silicon substrate is doped with an impurity to increase the number of carriers in the silicon substrate for suppressing optical crosstalk between the plurality of optical semiconductor devices, the optical waveguide is composed of a core part and a peripheral cladding layer of the core part, or optical fibers each coupled with each of the semiconductor devices, and an electrical resistivity of part or all of the silicon substrate is 0.

Abstract: In an optical module having a silicon substrate, a plurality of optical semiconductor devices and optical waveguides for performing transmission of optical signals by the semiconductor devices integrated on the silicon substrate, the silicon substrate is doped with an impurity to increase the number of carriers in the silicon substrate for suppressing optical crosstalk between the plurality of optical semiconductor devices, the optical waveguide is composed of a core part and a peripheral cladding layer of the core part, or optical fibers each coupled with each of the semiconductor devices, and an electrical resistivity of part or all of the silicon substrate is 0.

Abstract: An optical multiplexing/demultiplexing apparatus in which a plurality of optical multiplexing/demultiplexing units which are different from one another in operating wavelength band are connected hierarchically. Each of the optical multiplexing/demultiplexing units comprises an input waveguide for receiving a wavelength multiplexed optical waves, a filter for separating the wavelength multiplexed optical wave from the input waveguide into a first optical wave in the corresponding operating wavelength band and a second optical wave in the other wavelength bands, an AWG optical multiplexer/demultiplexer for separating the first optical wave from the filter into individual optical waves each of a single wavelength, and a branch waveguide for directing the second optical waves from the filter to the input waveguide of a succeeding optical multiplexing/demultiplexing unit.

Abstract: A packaging platform for optically coupling one or more optical waveguides of one or more optical components having the optical waveguide to one or more optical fibers is provided with a reference structure portion for the horizontal and vertical positioning of the optical component. The platform is further provided with one or more fiber positioning portions for inserting and holding the optical fiber and positioning the optical fiber at a position where the optical fiber is optically connected to the optical waveguide. The provided packaging platform and an optical module using the platform can simplify all alignment steps for optical coupling, electrical connection and sealing in the coupling of the optical component and the optical fiber.

Abstract: An opto-electronic hybrid integrated circuit of the present invention satisfies a low-loss optical waveguide function, an optical bench function and a high-frequency electrical wiring function. The circuit includes a substrate such as a silicon substrate, a dielectric optical waveguide part arranged in a recess of the substrate, and an optical device mounting part formed on a protrusion of the substrate. An electrical wiring part is disposed on the dielectric layer. The optical device is mounted on the substrate. An optical sub-module includes the optical device which is possible to mount on the substrate.

Abstract: An opto-electronic hybrid integrated circuit of the present invention satisfy a low-loss optical waveguide function, an optical bench function and a high-frequency electrical wiring function. The circuit includes a substrate such as a silicon substrate, a dielectric optical waveguide part arranged in a recess of the substrate, and an optical device mounting part formed on a protrusion of the substrate. An electrical wiring part is disposed on the dielectric layer. The optical device is mounted on the substrate. An optical sub-module includes the optical device which is possible to mount on the substrate.

Abstract: An opto-electronic hybrid integrated circuit of the present invention satisfy a low-loss optical waveguide function, an optical bench function and a high-frequency electrical wiring function. The circuit includes a substrate such as a silicon substrate, a dielectric optical waveguide part arranged in a recess of the substrate, and an optical device mounting part formed on a protrusion of the substrate. An electrical wiring part is disposed on the dielectric layer. The optical device is mounted on the substrate. An optical sub-module includes the optical device which is possible to mount on the substrate.

Abstract: An optical switching module has an optical waveguide substrate mounted on an electronic circuit substrate. According to a first aspect of the invention, the optical waveguide substrate has thin-film heaters, and the electronic circuit substrate has trimmable thick-film resistors for adjusting current fed to the thin-film heaters. According to a second aspect of the invention, the optical switching module also has a pair of fiber pigtails butt-coupled to the optical waveguide substrate. The fiber pigtails are secured to the ends of a supporter, which is attached to a heat sink fastened below the electronic circuit substrate. According to a third aspect of the invention, the optical waveguide substrate is mounted in a depression in the electronic circuit substrate. The invention reduces the size of the optical switching module.

Abstract: An optical fiber connector unit is composed of a ferrule including a first flange and a second flange formed to have a greater diameter than other portions, a stopring provided outside of the ferrule, having on its inner peripheral surface a first step and a second step, a coil spring having one end contacting with the first flange end face and the other end contacting with the first step end face, its tip exerting a spring force in an axial direction towards outside from the stopring; and a locating member provided between the stopring and the ferrule and having a first stopper contacting with the second step end face and a second stopper contacting with the second flange end face. The optical fiber connector using the unit can easily be assembled.

Abstract: A guided-wave circuit module includes a guided-wave circuit chip having an input waveguide part and an output waveguide part at the ends thereof, a guided-wave circuit part having a predetermined function and positioned between the input waveguide part and the output waveguide part; and a holder for supporting the guided-wave circuit chip, wherein the guided-wave circuit part of the guided-wave circuit chip does not come in contact with the chip holder; at least part of the input and output waveguide parts of the guided-wave circuit chip is fixed to the holder with a fixing agent; and the packaged chip does not have a warp which leads to deterioration of characteristics. A fixing agent having a high hardness is applied to the periphery of the endfaces of the input and output waveguide parts of the guided-wave circuit module and to the periphery of the fiber endfaces of the optical fiber array connected to the module.

Abstract: A waveguide-type optical matrix switch including as its switching element a Mach-Zehnder interferometer which includes two directional couplers and an optical phase shifter. The two directional couplers are arranged by placing two optical waveguides in close proximity at two positions on a substrate, and have an identical coupling ratio. The optical phase shifter is disposed over at least one of the two optical waveguides between the directional couplers. The two optical waveguides have an effective optical path length difference of half a wavelength of a light signal between the two directional couplers, and are intersected in the optical switch element. The waveguide-type optical matrix switch is little affected by fabrication errors in the coupling ratio of the directional couplers, and superior in the extinction ratio.