Abstract: The present invention is to provide a spot-size transformer which can transform the beam spot-size in a waveguide separated by a groove and a waveguide-embedded optical circuit using the spot-size transformer. The spot-size transformer according to the present invention comprises a first optical waveguide having a first core and a first cladding covering substantially the whole surface of the first core, a second optical waveguide having a second core provided as an extension of the first cladding and a second cladding, a transition waveguide positioned between the first and second optical waveguides, the transition waveguide having a first core whose width of the extension becomes gradually narrower as it goes toward the second optical waveguide.

Abstract: The present invention is to provide a spot-size transformer which can transform the beam spot-size in a waveguide separated by a groove and a waveguide-embedded optical circuit using the spot-size transformer. The spot-size transformer according to the present invention comprises a first optical waveguide having a first core and a first cladding covering substantially the whole surface of the first core, a second optical waveguide having a second core provided as an extension of the first cladding and a second cladding, a transition waveguide positioned between the first and second optical waveguides, the transition waveguide having a first core whose width of the extension becomes gradually narrower as it goes toward the second optical waveguide.

Abstract: The present invention relates to an optical module which can be produced by an easy process and at low cost and a method for fabricating the optical module. An optical module 100 includes a die pad 101, a plurality of leads 102, and a first platform 110 and a second platform 120 disposed on the die pad 101. At least an optical fiber 113 is fixed to a first platform body 111 and at least a light emitter 124 adapted for generating optical signals to be transmitted through the optical fiber 113 is mounted on a second platform body 121.

Abstract: The optical module includes a main housing, a light-emitting component supported by a second attachment section, a light-receiving component and a filter support member supported by a third attachment section, and first and second optical filters supported by the filter support member. The filter support member has a first surface and a second surface. The first optical filter is mounted on the first surface of the filter support member. The second optical filter is mounted on the second surface of the filter support member.

Abstract: An optical waveguide comprises a silica substrate, a buffer layer formed on the silica substrate, cores formed on the buffer layer, and upper cladding layer formed on the buffer layer, covering the cores. The thermal expansion coefficients of the buffer layer and upper cladding layer are set to be substantially equal. As a result, the stresses in the cores are isotropic, effectively suppressing birefringence.

Abstract: An optical waveguide comprises a silica substrate, a buffer layer formed on the silica substrate, cores formed on the buffer layer, and upper cladding layer formed on the buffer layer, covering the cores. The thermal expansion coefficients of the buffer layer and upper cladding layer are set to be substantially equal. As a result, the stresses in the cores are isotropic, effectively suppressing birefringence.

Abstract: A heat assisted magnetic recording head is provided, which can prevent an effect of a heat in a laser diode when a magnetic recording region is heated by a heating laser beam and which can reduce its size and weight. In the heat assisted magnetic recording head, a recording magnetic pole, a magnetic recording element, a magnetic read element, an optical waveguide, and an irradiating optical waveguide are attached to a floating slider provided below a suspension. The laser diode is arranged on an opposite side of the suspension to the floating slider. The heating laser beam emitted from the laser diode is directed to the irradiating optical waveguide through the optical waveguide, so that a magnetic recording medium is irradiated with the heating laser beam exiting from the irradiating optical waveguide.

Abstract: The present invention is to provide a spot-size transformer which can transform the beam spot-size in a waveguide separated by a groove and a waveguide-embedded optical circuit using the spot-size transformer. The spot-size transformer according to the present invention comprises a first optical waveguide having a first core and a first cladding covering substantially the whole surface of the first core, a second optical waveguide having a second core provided as an extension of the first cladding and a second cladding, a transition waveguide positioned between the first and second optical waveguides, the transition waveguide having a first core whose width of the extension becomes gradually narrower as it goes toward the second optical waveguide.

Abstract: The present invention is to provide an arrayed waveguide-embedded optical circuit with reduced loss at a groove and an optical functional element using for the arrayed waveguide-embedded optical circuit. The arrayed waveguide-embedded optical circuit according to the present invention comprises a waveguide, a groove formed across the waveguide and two or more spot-size transformer pairs whose members face each other across the groove.

Abstract: The optical module includes a main housing to which the optical fiber can be attached and a light-emitting component and a light-receiving component attached to the main housing. At least a part of a surface of the main housing has an irregular pattern to enhance a thermal dissipation. Because at least part of the main housing comprises a heat sink, so the optical module itself has a very high heat dissipation property, eliminating the type of problems that arise when adhesive or the like is used to attach to the main housing heat sinks constituted as separate parts, such as the increase in the number of parts and the degradation in thermal conductivity to the heat sink caused by the adhesive.

Abstract: An optical waveguide having low polarization dependence having a lower clad layer formed on a substrate, a core layer formed on the lower clad layer and an upper clad layer in which the core layer is buried. The core layer and the upper clad layer of the optical waveguide are made of a material comprising glass as a major component. The polarization dependence is lowered by optimizing the relationship between the coefficients of linear expansion softening temperatures of the optical waveguide layers.

Abstract: The invention relates to a silica optical waveguide having a clad layer and a core formed from a silica material and a method of fabricating the same and provides a silica optical waveguide in which the position of a core can be easily recognized and a method of manufacturing the same. The waveguide has a lower clad layer formed from silicate glass on a silica substrate, a core formed from silicate glass on the lower clad layer, and an upper clad layer formed of silicate glass on the lower clad layer so as to embed the core. A difference of height is provided on a top surface of the upper clad layer such that a difference between reflections from the position of the core and from other positions can be recognized on the top surface of the upper clad layer.

Abstract: The optical module includes a main housing to which the optical fiber can be attached and a light-emitting component and a light-receiving component attached to the main housing. At least a part of a surface of the main housing has an irregular pattern to enhance a thermal dissipation. Because at least part of the main housing comprises a heat sink, so the optical module itself has a very high heat dissipation property, eliminating the type of problems that arise when adhesive or the like is used to attach to the main housing heat sinks constituted as separate parts, such as the increase in the number of parts and the degradation in thermal conductivity to the heat sink caused by the adhesive.

Abstract: An optical waveguide comprises a silica substrate, a buffer layer formed on the silica substrate, cores formed on the buffer layer, and upper cladding layer formed on the buffer layer, covering the cores. The thermal expansion coefficients of the buffer layer and upper cladding layer are set to be substantially equal. As a result, the stresses in the cores are isotropic, effectively suppressing birefringence.

Abstract: The optical module includes a main housing, a filter support component, which can affix an optical fiber, supported by a first attachment section, a light-emitting component supported by a second attachment section, a light-receiving component supported by a third attachment section, and first and second optical filters supported by a filter support component. The filter support component has a first surface and a second surface. The first optical filter is mounted on the first surface of the filter support component. The second optical filter is mounted on the second surface of the filter support component.

Abstract: The optical module includes a main housing, a light-emitting component supported by a second attachment section, a light-receiving component and a filter support member supported by a third attachment section, and first and second optical filters supported by the filter support member. The filter support member has a first surface and a second surface. The first optical filter is mounted on the first surface of the filter support member. The second optical filter is mounted on the second surface of the filter support member.

Abstract: An optical waveguide is made of a glass based component, has low polarization dependence, and comprises a lower clad layer formed on a substrate, a core layer formed on the lower clad layer and an upper clad layer in which the core layer is buried, at least the core layer and the upper clad layer being made of a material comprising a glass as a major component, wherein if a coefficient of linear expansion of the core layer is denoted by ?core, a difference between a softening temperature Tcore of the core layer and a practically used temperature To by ?Tcore, a coefficient of linear expansion of the upper clad layer by ?clad, a difference between a softening temperature Tclad of the upper clad layer and the practically used temperature To by ?Tclad, and a coefficient of effective linear expansion of the substrate and of the lower clad layer by ?subs, then, a relationship, ? ? ? ? ? ? T core ? ? ? ? T clad = 2 ? ? core - ? subs - ? clad ? core - ? subs is satisfied.

Abstract: The optical branching device includes an input optical waveguide for outputting light inputted from a light input end face to a light output end face, a tapered optical waveguide having one end face connected to the light output end face and a width expanding at a predetermined angle, and branching optical waveguides connected to the other end face of the tapered optical waveguide at a predetermined branching angle, in which when a propagation constant of a leaky mode is ?L, a propagation constant of a fundamental mode is ?0, a meander period is ?, and ?=2?/(?0-?L), an optical waveguide length L from a position which becomes a cause of the leaky mode to the light output end face is substantially integer times ?/2.

Abstract: The invention relates to an optical branching circuit connected to a light output end face of an optical waveguide circuit or an optical branching circuit and for branching input light, and has a feature to provide an optical branching circuit with less branching ratio variation. The optical branching circuit is comprised of an input optical waveguide formed on a silica glass substrate and for outputting input light inputted from a light input end face to a light output end face, a tapered optical waveguide disposed to be shifted with respect to the input optical waveguide at the light output end face, and branching optical waveguides connected to a light output end face of the tapered optical waveguide at a predetermined branching angle.

Abstract: An optical waveguide is formed on a substrate 11 by the steps of (1) forming an lower clad layer 12, core layer 13, metal mask layer 14 and a photoresist layer 15, (2) patterning the photoresist layer 15 by using a photomask 16, (3) etching and patterning the metal mask layer 14 wider than a core of required width using the patterned photoresist layer 15, (4) removing the photoresist layer and the metal mask layer 14 after patterning the core layer 13 by using the patterned metal mask layer 14 to form core 13a, (5) forming an upper clad layer 17 on the lower clad layer 12 so as to bury the patterned core 13a.