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 multiplexer/demultiplexer is provided, which is easy to assemble and which can be manufactured with high productivity and a low cost. An optical multiplexer/demultiplxer includes a substrate formed with V-shaped grooves, optical fibers with a lens provided in tight contact with the V-shaped grooves, optical fiber securing plates, a base groove formed across the V-shaped grooves and an optical filter provided in the groove. First and second optical fibers with a lens are provided on either side of the base groove, and a third optical fiber is provided on the other side of the base groove. The optical fibers are provided such that the positions of their ends coincide with edges of the base groove. The third optical fiber with a lens is provided coaxially with the first optical fiber with a lens that is located on the other side of the base groove.

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.

Abstract: The present invention realizes miniaturization, low cost and improvement of fabricating efficiency of an optical module.

Abstract: The present invention realizes easy packaging of an optical module without using a molding machine and metal mold.

Abstract: An embedded type optically irreversible circuit device which achieves both low insertion loss and high return loss is provided, in which an optical element, comprised of an incoming side polarizer, a Faraday rotator, and an outgoing side polarizer superposed in the order of mention in the direction of an optical path, is embedded in the optical path of an optical fiber or optical waveguide having an light axis, the device has a slot extending across the light axis in a direction slanted with respect to the light axis, the optical element is inserted in the slot and the spaces between the optical element and the incoming and outgoing sides of the slot are filled with an optical adhesive portion; and at least one of interfaces between the incoming side polarizer, the Faraday rotator, the outgoing side polarizer and the optical adhesive portions is inclined at an angle reversely from the plane normal to the light axis as viewed from the slanted incoming side of the slot.

Abstract: Optical isolator comprises a ferrule having a through-hole in which an optical fiber is inserted and a groove formed in the ferrule with the optical fiber inserted in the through-hole; and a composite assembly consisting of an optical isolator element composed of a Faraday rotator and a pair of polarizers fixed on opposite surfaces of the Faraday rotator in such manner that the angle between the directions of polarization of the polarizers is at about 45° and a structure reinforcing member having a thickness of filling the groove and surrounding the optical element, said composite assembly being inserted in the groove as a unit. The reinforcing member may be made of the same material as the outer support or formed by a magnet for applying a magnetic field to the Faraday rotator.

Abstract: A composite optical element comprises a first optical material and a second optical material joined to one plane of a third optical material. The first and second optical materials are of equal thickness and having ground surfaces flush with each other on both of their principal planes. The first and second optical materials are fixedly joined to one another, and one of the principal planes of the two materials is ground. Then, the ground principal plane of the first and second optical materials is joined to the third optical material. Then, the other principal plane of the first and second optical materials is ground. A preferred embodiment is an optical isolator wherein the first and second optical materials are birefringent materials and are joined to one side of a Faraday rotator having a Faraday rotational angle of approximately 45°, and third and fourth birefringent materials are similarly joined to the other side of the rotator.

Abstract: A composite optical element comprises a first optical material and a second optical material joined to one plane of a third optical material. The first and second optical materials are of equal thickness and having ground surfaces flush with each other on both of their principal planes.The first and second optical materials are fixedly joined to one another, and one of the principal planes of the two materials is ground. Then, the ground principal plane of the first and second optical materials is joined to the third optical material. Then, the other principal plane of the first and second optical materials is ground.A preferred embodiment is an optical isolator wherein the first and second optical materials are birefringent materials and are joined to one side of a Faraday rotator having a Faraday rotational angle of approximately 45.degree. and third and fourth birefringent materials are similarly joined to the other side of the rotator.

Abstract: An optical fiber terminal provided with an optical isolator having a Faraday rotator, including an optical fiber retained in a ferrule, an optical isolator element, and a permanent magnet for applying a magnetic field to the Faraday rotator is improved to provide a minimum possible outer diameter. The fiber terminal comprises an attaching member for fixedly attaching the optical isolator and the permanent magnet to the ferrule together; an air layer between an end of said optical fiber and said optical isolator element; a first outer diameter of said ferrule on the side of the optical isolator constituting a maximum diameter of the optical fiber terminal, a second outer diameter of said ferrule on the side of the optical fiber being smaller than the first maximum diameter; and the periphery of the permanent magnet being exposed to the air.

Abstract: In an optical isolator including first and second birefringent plates whose optical axes are angularly different and a Faraday rotator inserted therebetween having a Faraday rotation angle of .theta..sub.f, (1) the angles of the optical axes of the first and second birefringent plates are so set that a forward incident polarized light passes through the first and second birefringent plates both as ordinary lights or both as extraordinary lights, and the relationship .theta..sub.f +.phi..sub.eff =90.degree. is satisfied when an actually used incident polarized light is incident in an oblique direction, or (2) the angles of the optical axes of the first and second birefringent plates are so set that a forward incident polarized light passes through one of the first and second birefringent plates as an ordinary light and the other birefringent plate as an extraordinary light, and the relationship .theta..sub.f -.phi..sub.eff =0.degree. is satisfied.

Abstract: An optical fiber terminal fitted with an optical isolator in close proximity in a unitary structure comprises an optical fiber, a ferrule which holds the optical fiber in position, at least one magneto-optical element located as aligned with the optical fiber, and a cylindrical permanent magnet that applies a magnetic field to the magneto-optical element. The magneto-optical element is disposed axially outside of the magnet, and the end face of the optical fiber is located in the hollow of the magnet or in the space between the magnet and the magneto-optical element, so that the overall outside diameter and length can be decreased. The ferrule, made of a soft magnetic material, increases the magnetic field strength of the magnet.

Abstract: An optical fiber terminal fitted with an optical isolator comprises an optical fiber, a ferrule which holds the optical fiber in position, and an optical isolator which includes an optical isolator assembly having at least one magneto-optical element and at least one polarizer and means for applying a magnetic field of less than saturation to the magneto-optical element. The fiber, ferrule, and isolator are disposed close to one another and joined integrally. The optical isolator has a maximum outside diameter not more than twice, preferably substantially equal to, the outside diameter of the ferrule.