Abstract: A method for manufacturing high-precision end faces on waveguides, by which the end face of a waveguide formed in a substrate contains microscopically small fractures due to mechanical processing, is characterized by the procedural steps: place a body (20) having a high-precision surface against the substrate (10) in front of the end face of the waveguide (12); introducing an adhesive (22) into the space between the end face of the waveguide (12) and the high-precision surface of the body (20); and allowing the adhesive (22) to set.

Abstract: An optical plug connector for an optical measuring device between an internal light waveguide optical fiber and an external light waveguide optical fiber maintains a distance d between the ends of the fibers which is greater than the coherence length of the light to be transmitted through the coupling. In this manner, in spite of the presence of the air gap, interference phenomena are avoided.

Abstract: A new type of optical power attenuator of the variable attenuation type. The optical connector ferrule edges are finished by polishing them at an inclination angle of seven to 12 degrees with respect to the optical axis thereof, and both ferrule edges face each other with a gap therebetween. One of the ferrule edges is fastened not so that it can be rotated whereas the other can be rotated around its optical axis. The attenuation is determined by both the inclination and gap, and it can be set stably by adjustment of the angle of the rotation around the optical axis of the ferrules.

Abstract: An optical module comprises at least one optical sub-module having at least one optical connector for receiving an end portion of an optical fiber at an end portion of the optical connector so as to optically couple the end portion of the optical fiber with an optical operation element, and a molded resin member for holding the optical connector except for the end portion of the optical connector; and at least one receptacle for enveloping the end portion of the optical connector to integrally hold the optical sub-module, the receptacle having an opening portion for fitting with an optical plug holding the end portion of the optical fiber which is to be received by the optical connector. The receptacle is resin-molded by using a mold die including a core for forming an opening portion of the optical module, the core having at least one hold portion for holding a portion of the optical sub-module.

Abstract: There is provided by this disclosure a fiber optical connector assembly for mating and demating optical fibers in a contaminated air or an underwater environment. Elastomeric seals having normally closed apertures cover the mating end of the male and female connecting members to seal and protect the abutting ends of optical fibers within the connector assembly in a contaminant free fluid. The surface of each mating end has regions of convexity and concavity forming peaks and valleys to seal and maintain a contaminate free environment when the male and female connecting members are brought together. A locking means is provided for automatically locking the connecting members in the mated position to prevent axial, angular, transverse, or rotational movement at the optical interface. The connecting members are configured to store a predetermined length of optical fiber as a service loop to facilitate multiple terminations to the optical fiber without the need to rework the termination to the cable itself.

Abstract: This disclosure describes a precision optical fiber connection system buildable with a minimum of precision-made components. Sets of fibers to be mated are contained in V-grooves in respective opposing silicon-etched fiber holders. A lense-sphere is fixedly deployed in the groove next to the end of each fiber. An initial gross positioning of the lense-spheres of the upper fiber holders with respect to their receiving grooves in the lower fiber holder, is achieved by using a cylinder disposed adjacent to the fiber grooves. Tapered sides of the upper holders engage the cylinder to funnel the lense-sphere into their receiving grooves. Also disclosed is a three-point support system for assuring that the opposing fiber groove surfaces remain parallel and do not experience relative rotation.

Abstract: A fiber optic attenuator having a predetermined, fixed attenuation value and low back reflection properties across a broad wavelength spectrum is disclosed. Attenuation is achieved by providing an optical fiber pathway having an attenuation region which causes a predetermined signal loss. The medium defining the pathway is of a substantially constant index of refraction through the device to minimize or eliminate interference caused by Fresnel reflections.

Abstract: A fiber optic connector includes a plug having a ferrule adapted to be connected to a tip end of an optical fiber, a receptacle associated with a light-emitting element and having a ferrule insertion hole defined therein for receiving the plug therein, the ferrule insertion hole being held in light-transmitting communication with the light-emitting element, the receptacle being arranged such that the receptacle establishes an optical path between the light-emitting element and the optical fiber for optical coupling therebetween when the ferrule is inserted into the ferrule insertion hole, and a light blocking element for interrupting the optical path within the ferrule insertion hole in response to insertion of the ferrule into the ferrule insertion hole.

Abstract: A terminus for an end portion of an optical fiber has a ferrule with a relatively large passageway extending from an open end to a cylindrical endwall portion, the latter having an opening only slightly larger than fiber glass core with cladding diameter. An optical fiber to be terminated has an end portion stripped of buffer coating and located in the ferrule with the bare glass portion in the smaller opening. A first epoxy secures the fiber within the ferrule. With the fiber end faced-off and polished, the flat face of a plano-convex lens is secured to the ferrule endwall and fiber end by a second epoxy having optical characteristics closely watching those of the lens and fiber. A cylindrical hood fits over the lens and ferrule end. A pair of such terminations are slid into opposite ends of an alignment tube positioning for optical signal transmission.

Abstract: A cylindrical ferrule type optical fiber connector (20) includes an attenuator arrangement which includes an element (70) that is capable of movement during the assembly of the connector. The connector includes a cylindrically shaped sleeve (60) which has a longitudinally extending slot (61) formed through the wall thereof and which is adapted to receive a cylindrical plug (40) in each end thereof, each plug being spring-biased outwardly from a cap (45) and terminating an optical fiber (21). The attenuator element has a disc-shaped portion (74) which is disposed within the sleeve. A neck portion (76) which extends through the slot of the sleeve connects the disc-like portion to a supporting head portion (72) which engages an outer surface of the sleeve. As a first one plug is inserted into the sleeve, it engages the attenuator element and causes it to be moved along the slot in the sleeve.

Abstract: A variable light attenuator of optical connector type. It consists of an alignment adapter, first ferrule fastening means, and second ferrule fastening means. The alignment adapter provides an alignment through hole concentrically passing therethrough along the optical axis thereof. First ferrule fastening means fastens first ferrule whose edge is exposed to an intermediate air gap and is 7 degrees or more inclined to a plane perpendicular to the optical axis, passes the first ferrule through the alignment through hole, and fastens the first ferrule to the alignment adapter. Second ferrule fastening means fastens second ferrule which is almost the same as first ferrule fastening means in both structure and functions, but movable along the optical axis to appropriately set the gap between the first and second ferrules while the edges of the first and second ferrules are kept in parallel by key pin and key groove to specify the designated attenuation.

Abstract: A low loss, tunable optical filter (20) comprises two ferrules (24--24) which are aligned axially with each of two adjacent end faces being provided with a wafer (30). A mirror (40) is embedded between each end face and its associated wafer, the wafer being bonded to the end face of its associated wafer. Optical fiber is disposed in a passageway which extends through each ferrule and through the associated wafer. The ferrules and associated wafers are supported to cause adjacent exposed faces of the wafers to be in predetermined spatial relation to each other. Any gap therebetween may be fixed or may be adjusted by a piezoelectric transducer system (44). The disclosed filter provides rejection ratios which are sufficiently high for frequency discrimination in frequency shift keying systems and for channel selection or switching in wave division multiplexer applications.