Abstract: A tape optical fiber cord with an optical fiber array has, at its one end, a half pitch fiber array connected to an optical waveguide. Connectors are connected respectively to connector-side optical fibers located at the other end of the tape optical fiber cord. A branching case for branching the connector-side optical fibers is provided in a position between both ends of the cord. One end of a tape fiber comprising tapes arranged in two columns of two stages is fixed to the half pitch fiber array, and the other end is fixed in a fixation section within the branching case to the case. In the portion intermediate between the two fixed portions, the connector-side optical fibers are separated one by one, and the outside of the separated optical fibers is covered with a protective tube while leaving a space between the protective tube and the separated optical fibers.

Abstract: A tape optical fiber cord with an optical fiber array has, at its one end, a half pitch fiber array connected to an optical waveguide. Connectors are connected respectively to connector-side optical fibers located at the other end of the tape optical fiber cord. A branching case for branching the connector-side optical fibers is provided in a position between both ends of the cord. One end of a tape fiber comprising tapes arranged in two columns of two stages is fixed to the half pitch fiber array, and the other end is fixed in a fixation section within the branching case to the case. In the portion intermediate between the two fixed portions, the connector-side optical fibers are separated one by one, and the outside of the separated optical fibers is covered with a protective tube while leaving a space between the protective tube and the separated optical fibers.

Abstract: The present invention provides a measuring device for an arrayed waveguide diffraction grating that enables accurate measurement of the optical path length for 1.5 &mgr;m wavelength light in an arrayed waveguide diffraction grating. The present invention's measuring device for an arrayed-waveguide diffraction grating is provided with a first light source 10; a first optical path, onto which light radiated from first light source 10 is introduced and on which an arrayed-waveguide diffraction grating 14 which is the measurement target is disposed; a second optical path, on which an optical path length varying means 18 is disposed; and a Mach-Zehnder interference optics system for causing interference in light that has passed through the first optical path and the second optical path.

Abstract: A waveguide path type polarization independent optical wavelength tunable filter includes two polarization beam splitters consisting of Ti diffusion optical waveguide paths and anisotropic waveguide paths formed on a dielectric surface, respectively, and a mode converter consisting of the Ti diffusion optical waveguide path, a surface acoustic wave interdigital transducer and an acoustic wave absorber. A layered film consisting of an SiO2 film and an Si film is formed right on the Ti diffusion optical waveguide paths of the polarization beam splitters and a metal film is formed right on the anisotropic optical waveguide paths. By so arranging, the TE polarization component of a non-selected light and the TM polarization component of a non-selected light, both of which are noise components for filter characteristics, are absorbed and removed by the layered SiO2 and Si films and the metal film.

Abstract: A waveguide type polarization scrambler is provided with; a Mach-Zehnder interferometic waveguide having the first input and output optical waveguides and second output and output waveguides on a dielectric substrate, a phase modulator having the third input output optical waveguides and fourth input and output waveguides and second input and output optical waveguides are connected to the third input and output waveguides, a light input means for inputting a light signal to the first input and output optical waveguides, and a light output means for receiving the light emitted from the fourth input and output optical waveguides. It is possible to apply tolerant device fabrication process conditions without complex fabrication process and possible to adjust easily the output light to randomized polarization state without exact adjustment of the optical axis.

Abstract: In an optical waveguide electrically controlled variable attenuator using a dielectric substrate, light which has entered from the input port is split into TM mode and TE mode by a polarization beam splitter. After these modes are variably attenuated by respective directional coupler switches, a resulting TM mode and TE mode are coupled by a polarization coupler and output from the output port. Control voltages of the directional coupler switches are adjusted to a fixed ratio in such a manner that equal attenuation characteristics will be obtained for both the TM and TE modes. This makes it possible to obtain an attenuation characteristic that is independent of the polarized light.

Abstract: A waveguide type optical switch comprises a substrate having an electro-optical effect, a directional coupling type switch portion including two optical waveguides formed on the substrate for effecting optical switching by optical coupling. The waveguide switch includes a branched interfering portion provided on at least one of the two optical waveguides of the directional coupling switch portion, for controlling an intensity of light output from the directional coupling switch portion to obviate polarization dependency.

Abstract: Side planes of input and output waveguides are exposed in a waveguide type optical device by etching. The exposed side planes are covered with deposited metal films. A TM mode light is propagated through the input and output waveguides without being badly affected by the metal films, but a TM mode light is absorbed by the metal films.