136results about How to "Reduced propagation loss" patented technology

In an electro-optic device, a stack structure including a first silicon layer of a first conductivity type and a second silicon layer of a second conductivity type has a rib waveguide shape so as to form an optical confinement area, and a slab portion of a rib waveguide includes an area to which a metal electrode is connected. The slab portion in the area to which the metal electrode is connected is thicker than a surrounding slab portion. The area to which the metal electrode is connected is set so that a range of a distance from the rib waveguide to the area to which the metal electrode is connected is such that when the distance is changed, an effective refractive index of the rib waveguide in a zeroth-order mode does not change.

Provided is a near-field light generating element in which reduced is the propagation loss of excited surface plasmon that propagates to the near-field light generating end. The element comprises: a waveguide through which light for exciting surface plasmon propagates; and a plasmon antenna comprising a near-field light generating end and a propagation surface or edge. The propagation surface or edge extends to the near-field light generating end, and causes surface plasmon excited by the light to propagate thereon. Further, a portion of the side surface on the near-field light generating end side is opposed to the propagation surface or edge with a predetermined distance so as for the light to be coupled with the plasmon antenna in a surface plasmon mode. In this configuration, surface plasmon can propagates without significantly changing its wavenumber, which leads to a less propagation loss, and to an improved light use efficiency.

The present invention relates to an assembly of multiple waveguides which includes a substrate and a plurality of waveguides positioned on said substrate at locations effective to suppress cross-talk between different waveguides. The plurality of waveguides each comprise an elongate array of quantum dots extending between sets of first and second locations on the substrate. The waveguides are positioned to receive: (1) pumped light uniformly applied to the array to produce electron-hole pairs and to enable optical gain and (2) signal light at the first location to trigger an emission from the quantum dot at the first location and transmission of photons along the array to the second location. A light transmission system which includes this assembly as well as methods of making and using the assembly are also disclosed.

A method of producing a polymer optical waveguide, including: preparing a mold; preparing a lower film base material; introducing a core-forming curable resin into a first through-hole of the mold with which the lower film base material is brought into close contact while sucking the concave portion of the mold from a second through-hole under reduced pressure to introduce the core-forming curable resin into the concave portion of the mold; curing the core-forming curable resin which has been introduced; removing the mold from the lower film base material; providing a clad-forming curable resin layer and an upper film base material, the clad-forming curable resin layer being sandwiched between the lower film base material, on which the core is formed, and the upper film base material; and curing the clad-forming curable resin layer to fix the lower film base material and the upper film base material.

An opto-electric hybrid module capable of reducing the propagation loss of light beams, and a manufacturing method thereof. An opto-electric hybrid module in which a light-emitting element and a light-receiving element are mounted on the front surface side of an electric circuit board E, and an optical waveguide W1 is bonded to the back surface side thereof. The optical waveguide W1 includes a core having opposite end portions formed as light reflection portions. Portions of the core near the opposite end portions are formed as extensions extending from the light reflection portions toward the light-emitting element and the light-receiving element. The extensions and are positioned in through holes for light propagation formed in the electric circuit board E, and have distal end surfaces and in face-to-face relationship with a light-emitting portion of the light-emitting element and a light-receiving portion of the light-receiving element, respectively.

A method is provided for forming a waveguide region within a periodically domain reversed ferroelectric crystal wherein the waveguide region has a refractive index profile that is vertically and horizontally symmetric. The symmetric profile produces effective overlapping between quasi-phasematched waves, a corresponding high rate of energy transfer between the waves and a symmetric cross-section of the radiated wave. The symmetric refractive index profile is produced by a method that combines the use of a diluted proton exchange medium at a high temperature which produces a region of high index relatively deeply beneath the crystal surface, followed by a reversed proton exchange which restores the original crystal index of refraction immediately beneath the crystal surface.

In an electro-optic device, a stack structure including a first silicon layer of a first conductivity type and a second silicon layer of a second conductivity type has a rib waveguide shape so as to form an optical confinement area, and a slab portion of a rib waveguide includes an area to which a metal electrode is connected. The slab portion in the area to which the metal electrode is connected is thicker than a surrounding slab portion. The area to which the metal electrode is connected is set so that a range of a distance from the rib waveguide to the area to which the metal electrode is connected is such that when the distance is changed, an effective refractive index of the rib waveguide in a zeroth-order mode does not change.

An optical modulator includes a waveguide Mach-Zehnder interferometer having a first and a second input and a first and a second output, a feedback waveguide segment connecting the second output with the second input, and a traveling-wave electrode; wherein the Mach-Zehnder interferometer, feedback waveguide segment and traveling-wave electrode are substantially arranged at or adjacent the perimeter of a smooth curve defining a closed geometric figure, the traveling-wave electrode extending along at least 50% of the length of the perimeter of the smooth curve.

An optical device integrated head having high light utilizing efficiency by decreasing the propagation loss caused from an optical source to a recording medium, conducting by mounting according to compact active alignment method for efficiently guiding a light generated from a laser device to the top end of a head, in which a light source device mounted on a submount has a mirror portion having an inclinated surface to at least a portion of one edge thereof for reflecting an output light from the optical source device at the inclinated surface, a structural member including a lens structure for further allowing a light to pass through the submount, and an optical waveguide disposed passing through a slider for mounting the submount, and the optical source and the slider are positioned by using active alignment of light in a chip-on carrier structure having the optical source device mounted on the submount.

A photonic bandgap fiber includes a core and a cladding that surrounds the core. In this photonic bandgap fiber, high refractive index portions which have a refractive index higher than that of a medium of the cladding are provided in the cladding so as to form a triangular lattice structure with a lattice constant Λ, and the refractive index of the core is higher than the refractive index of the medium of the cladding and lower than the refractive index of the high refractive index portion. The coupling length between the core and the high refractive index portion that is closest to the core is longer than the coupling length between adjacent high refractive index portions, or a periodic structure formed by the high refractive index portions is not provided around the entirely of the area along the circumference of the core.

An image sensing device is disclosed. The image sensing device comprises a plurality of image sensor units disposed separately and a plurality of wave guiding units. Each wave guiding unit is disposed on each corresponding image sensor unit. The image sensing device can avoid diffraction and crosstalk. In addition, since each interlayer distance is short, the effect to isolate beams and reduce propagation loss is reached to some degree.

A single pole single throw switch for controlling propagation of a high frequency signal between an input terminal (11a) and an output terminal (11b). First FET switches (14a, 14b) in which drains and sources of FETs (12a, 12b) are connected in parallel with inductors (13a, 13b) are connected in parallel. Each FET (12a, 12b) is switched between on state and off state by a voltage being applied to the gate thereof. At the frequency of the high frequency signal, each inductor (13a, 13b) connected with off capacitor of each FET (12a, 12b) resonates in parallel.

An optical device fabrication method capable of fabricating optical devices with high precision and reliability in a simple process and at a low cost. The method of splicing a first optical device and a second optical device to fabricate a third optical device includes the steps of: (a) starting heating of an end surface of the first optical device to soften the end surface; (b) pushing the second optical device into the softened end surface to splice the first optical device and a joint surface of the second optical device to each other; (c) pulling back the second optical device to arrange the joint surface of the second optical device onto or outside of the end surface of the first optical device; and (d) terminating heating of the end surface to fix the first and second optical device spliced to each other.

A gradient index lens for electromagnetic radiation includes a dielectric substrate, a plurality of conducting patches supported by the dielectric substrate, the conducting patches preferably being generally square shaped and having an edge length, the edge length of the conducting patches varying with position on the dielectric substrate so as to provide a gradient index for the electromagnetic radiation. Examples include gradient index lenses for millimeter wave radiation, and use with antenna systems.

A photonic bandgap fiber includes a core and a cladding that surrounds the core. In this photonic bandgap fiber, high refractive index portions which have a refractive index higher than that of a medium of the cladding are provided in the cladding so as to form a triangular lattice structure with a lattice constant Λ, and the refractive index of the core is higher than the refractive index of the medium of the cladding and lower than the refractive index of the high refractive index portion. The coupling length between the core and the high refractive index portion that is closest to the core is longer than the coupling length between adjacent high refractive index portions, or a periodic structure formed by the high refractive index portions is not provided around the entirely of the area along the circumference of the core.

In a thermally assisted recording head using a conductive scatterer as an optical near-field transducer, a propagation loss in a waveguide for guiding light to the scatterer is reduced. An optical near-field is generated by using the conductive scatterer having a width that gradually becomes smaller toward a vertex at which the optical near-field is generated. At the same time, a height of the conductive scatterer for generating the optical near-field is made substantially equal to a height of a main pole or longer than the height of the main pole.

A low loss micro-ring resonator device which has a closed-loop resonator waveguide having a first refractive index, the resonator waveguide defining an inner and an outer region by an outer curved edge of the waveguide. The resonator waveguide is arranged on a substrate having a second refractive index, the refractive index difference between the first refractive index and the second refractive index is greater than 0.3. The device also has an upper cladding covering the inner region of the resonator waveguide having a third refractive index and a lateral cladding in contact with the outer curved edge and extending in the outer region, the lateral cladding having a fourth refractive index, the fourth refractive index being lower than the third refractive index. A method for reducing propagation losses of a resonator device is also described.

A single pole single throw switch for controlling propagation of a high frequency signal between an input terminal (11a) and an output terminal (11b). First FET switches (14a, 14b) in which drains and sources of FETs (12a, 12b) are connected in parallel with inductors (13a, 13b) are connected in parallel. Each FET (12a, 12b) is switched between on state and off state by a voltage being applied to the gate thereof. At the frequency of the high frequency signal, each inductor (13a, 13b) connected with off capacitor of each FET (12a, 12b) resonates in parallel.