Abstract: A silica based glass waveguide having almost the same optical characteristics as designed value and an optical module using a silica based glass waveguide having excellent optical characteristics and reduced connecting loss are provided. A silica based glass waveguide is comprising a core waveguide and a clad, a core waveguide is formed rectangular in cross section and of SiO2—TiO2 group glass on a synthetic silica glass substrate, and a clad is formed of SiO2—B2O3—P2O5 group glass or etc. on a synthetic silica glass substrate and a core waveguide. A synthetic silica glass substrate is formed of pure SiO2 and having birefringence quantity less than 10 nm/cm.

Abstract: A method for fabrication of a multilayered optical waveguide structure which includes at least two substrates, and an optical waveguide layer disposed between the substrates and having at least one core region and side cladding regions laterally succeeding from the core region. The method is characterized in that the optical waveguide layer is formed from a polysilane compound containing polysilane, and it comprises stacking a first block including one of the substrates and a second block including the other of the substrates through the optical waveguide layer or a cladding layer located at a surface of either one of the blocks, and heating them while pressed in such arrangement so that the first block and the second block are bonded together by the optical waveguide layer or the cladding layer serving as a bonding layer into the multilayered structure.

Abstract: A photoelectric composite connector comprises a first connector unit which is connected to optical transmission means and a second connector unit which can be attached to and detached from a first connector unit freely. The first connector unit comprises a photoelectric conversion module and an electrical connector section having a first conductor which is electrically connected to the photoelectric conversion module. The second connector unit is formed as an electrical connector unit corresponding to the electrical connector section of the first connector unit and having a second conductor. The first conductor of the electrical connector section of the first connector unit and the second conductor of the second connector unit are electrically connected to each other when the electrical connector section of the first connector unit and the second connector unit are connected to each other by use of their electrical connector structures.

Abstract: An optical switching apparatus and a method of efficiently switching optical signals are disclosed. Optical insertion loss may be reduced in a planar lightwave circuit by determining an optimal spacing between perturbations including using passive perturbations, having a three dimensional refractive index distribution, in an array of waveguides, or by adjusting parameters of existing perturbations e.g. their spacing. The perturbation and each waveguide have different three dimensional refractive index distributions. The perturbation may be positioned anywhere in the array of waveguides. The perturbation may be a trench, a region of refractive index different from that in each waveguide, a broken waveguide core, or a modification of the topography of the array of waveguides. In one embodiment, the perturbation is a periodic or quasiperiodic perturbation.

Abstract: A silica based glass waveguide having almost the same optical characteristics as designed value and an optical module using a silica based glass waveguide having excellent optical characteristics and reduced connecting loss are provided. A silica based glass waveguide is comprising a core waveguide and a clad, a core waveguide is formed rectangular in cross section and of SiO2-TiO2 group glass on a synthetic silica glass substrate, and a clad is formed of SiO2-B2O3-P2O5 group glass or etc. on a synthetic silica glass substrate and a core waveguide. A synthetic silica glass substrate is formed of pure SiO2 and having birefringence quantity less than 10 nm/cm.

Abstract: An optical switching apparatus and a method of efficiently switching optical signals are disclosed. Optical insertion loss may be reduced in a planar lightwave circuit by determining an optimal spacing between perturbations including using passive perturbations, having a three dimensional refractive index distribution, in an array of waveguides, or by adjusting parameters of existing perturbations e.g. their spacing. The perturbation and each waveguide have different three dimensional refractive index distributions. The perturbation may be positioned anywhere in the array of waveguides. The perturbation may be a trench, a region of refractive index different from that in each waveguide, a broken waveguide core, or a modification of the topography of the array of waveguides. In one embodiment, the perturbation is a periodic or quasiperiodic perturbation.

Abstract: An optical switch for switching an optical path of an input optical signal comprises a substrate composed of a silica glass substrate, a separation layer formed on the silica glass substrate, a plurality of cantilever beams and formed in parallel to one another on the separation layer and connected at their tip ends to a connection member, at least one silica glass optical waveguide core formed on the cantilever beams, a plurality of optical waveguide fixed in opposition to the silica glass optical waveguide core, a cover for covering the cantilever beams, and a switch drive unit for bending the cantilever beams. The switch drive unit comprises electromagnetic actuators, which comprise soft magnetic bodies formed on the connection member for the cantilever beams and on the substrate, soft magnetic yokes formed of a soft magnetic body, permanent magnets, and wire coils.

Abstract: An optical switch for switching an optical path of an input optical signal comprises a substrate composed of a silica glass substrate, a separation layer formed on the silica glass substrate, a plurality of cantilever beams and formed in parallel to one another on the separation layer and connected at their tip ends to a connection member, at least one silica glass optical waveguide core formed on the cantilever beams, a plurality of optical waveguide fixed in opposition to the silica glass optical waveguide core, a cover for covering the cantilever beams, and a switch drive unit for bending the cantilever beams. The switch drive unit comprises electromagnetic actuators, which comprise soft magnetic bodies formed on the connection member for the cantilever beams and on the substrate, soft magnetic yokes formed of a soft magnetic body, permanent magnets, and wire coils.

Abstract: An optical switch for switching an optical path of an input optical signal comprises a substrate composed of a silica glass substrate, a separation layer formed on the silica glass substrate, a plurality of cantilever beams and formed in parallel to one another on the separation layer and connected at their tip ends to a connection member, at least one silica glass optical waveguide core formed on the cantilever beams, a plurality of optical waveguide fixed in opposition to the silica glass optical waveguide core, a cover for covering the cantilever beams, and a switch drive unit for bending the cantilever beams. The switch drive unit comprises electromagnetic actuators, which comprise soft magnetic bodies formed on the connection member for the cantilever beams and on the substrate, soft magnetic yokes formed of a soft magnetic body, permanent magnets, and wire coils.

Abstract: An optical waveguide comprises an anhydrous synthetic silica glass substrate 1, which contains less than a predetermined concentration of hydroxyl group, a core waveguide 2 having a rectangular cross-section being formed on the substrate 1, and a cladding layer 3 having a lower refractive index thereof than the core waveguide 2 being covered by the cladding layer 3. The concentration of hydroxyl group contained in a synthetic silica glass substrate of an optical waveguide or an optical device is essentially less than 300 ppm, preferably less than 100 ppm, more preferably less than 50 ppm.

Abstract: An optical waveguide 3 comprises a substrate like a Si substrate having a projection with a flat surface and inclined side surfaces thereon, a buffer layer having a refractive index of n.sub.0 formed on lower surfaces of the substrate, a secondary buffer layer having a refractive index of n.sub.0 formed on the buffer layer, a core waveguide having a refractive index of n.sub.1 formed on the secondary buffer layer and a cladding layer having a refractive index of n.sub.0 covering the core waveguide. The flat surface of the projection 31 is exposed through an opening. The secondary buffer layer controls a transmission loss increase caused by partial thickness differences of the ground buffer layer or scattering by scratches or strains created by the grind.