Lucent Technologies Inc.

At&t Bell Laboratories

Fitel USA Corporation

Wilton Wayt King

William Roger Lambert

Robert William Filas

Charles Joseph Aloisio

Norman Roger Lampert

George J Shevchuk

Daniel Lee Stephenson

Jerry Max Anderson

Ruben Travieso

Ray R Cammons

Daniel L Stephenson

Claire H Plagianis

An optical fiber connection device is disclosed that allows for in situ variable attenuation of a signal transmitted between two optical fibers. The connection device comprises an attenuator element fabricated with an inherently compliant, elastomeric material, preferably a silicone elastomer. The elastomeric properties of the attenuator element allow for varying the thickness of the attenuator element and thereby changing the level of attenuation in situ. Silicone elastomers are preferred for fabricating the attenuator element as applicants have discovered they may be index-matched to optical transmission fibers, have a high creep modulus, exhibit relatively constant mechanical properties over a broad range of temperatures, and are reliable upon exposure to varied environmental conditions.

Variable optical fiber attenuator device

An improved optical fiber connection system comprises an attenuator element fabricated with an inherently elastomeric material, preferably a silicone elastomer. Silicone elastomers are particularly preferred for fabricating attenuator elements as they may be index-matched to optical transmission fibers, have a high creep modulus, exhibit relatively constant mechanical properties over a broad range of temperatures, and are reliable upon exposure to varied environmental conditions. Preferably, a disc-like attenuator element is punch-cut from a sheet of a silicone elastomer and inserted into the sleeve of an optical connector apparatus adjacent the end portion of an optical fiber to provide a simplified method of fabrication. Alternatively, the silicone attenuator element may be fabricated by liquid injection molding technology. The approximate reflectance of the inventive silicone attenuators at wavelengths of about 1310 nm measured at 23.degree. C. is less than -50 dB.

Optical fiber attenuator device using an elastomeric attenuator member

An optical terminator 100 is designed to make end-to-end contact with an optical fiber whose end portion is held within a cylindrical ferrule. The optical terminator reduces reflections that occur when an optical path encounters an abrupt change in refractive index (e.g., when the end portion of the optical fiber encounters an air gap whose refractive index n.apprxeq.1.0). The optical terminator includes a generally cylindrical member 110 that projects from, and is supported by, a backbone member 120. The cylindrical member and the backbone member are molded from polymethyl methacrylate (PMMA) as a one-piece structure. PMMA provides a reflection of about -40 dB. Nevertheless, plastic materials having an index of refraction of 1.46.+-.0.06 produce reflections that are less than about -34 dB, which is acceptable in a large number of applications. Moreover, plastic materials having a glass-transition temperature (T.sub.g) that is higher than about 80.degree. C., exhibit minimum indentation creep under a compressive load at elevated temperatures. In one embodiment, the optical terminator 100 is spring loaded within a connector housing 45. In another embodiment, the spring 44 is eliminated and a connector housing is integrally molded with the optical terminator as a one-piece structure 70.

Thermo-plastic optical terminator having a glass-transition temperature

A closed alignment sleeve has three lands equally spaced on the inside surface of the sleeve. When a ferrule is inserted into the sleeve, the interference at the three lands causes the walls of the sleeve to bend to accommodate the ferrule. In this manner, the closed alignment sleeve with three lands has a stiffness attained by the mechanism normally associated with the open sleeve. The closed alignment sleeve is symmetrical and the three lands act to center the ferrule within the sleeve. The sleeve is formed from a thermoplastic which is much less expensive and much more compliant than conventional ceramic and which allows the sleeve to deform to the size of the ferrule. Further, the envelope required to contain the sleeve is small enough to fit within a variety of optical connectors, including the SC connector.

Closed alignment sleeve for optical connectors

An optical terminator 100 is designed to make end-to-end contact with an optical fiber 31 whose end portion is held within a cylindrical ferrule 400. The optical terminator minimizes reflections that occur when an optical path encounters an abrupt change in refractive index (e.g., when the end face of the optical fiber encounters an air gap). The optical terminator comprises a solid cylindrical structure, molded from a polymeric material (e.g., a methylpentene copolymer) having a refractive index similar to that of the optical fiber. The proximal end of the terminator abuts the cylindrical ferrule and is solid for a predetermined distance `d` along its longitudinal axis in order to provide at least 20 dB attenuation. The polymeric material is moldable and exhibits minimum indentation creep under a compressive load at elevated temperatures. In one embodiment, the terminator 100 is installed in a plug configuration. In this configuration, a coupling apparatus 20 is needed to interconnect the connector 40 that holds an optical fiber with the plug terminator 10 that holds the terminator. In another embodiment, the terminator 100 is installed within a receptacle configuration. In this configuration, the connector 40 that holds the optical fiber can be directly attached to the receptacle terminator 50.

Optical terminator

In order to mount optical fiber connectors in a panel (22), the panel is provided with a plurality of openings in each of which is disposed a buildout system. Each buildout system includes a buildout block each having a portion disposed on a rear side of the panel and adapted to have an optical fiber connector assembled thereto. Any one of three buildout blocks may be used in order to receive a desired connector which may be an ST, SC, or FC connector. Secured through a latching arrangement to the portion of the buildout block on a front side of the panel is a buildout which may have any one of three configurations to accept any one of the three connectors. The latching arrangement between buildout block and buildout is the same for any combination of buildout block and buildout. As a result of the structure of the buildout system, a buildout and a buildout block may be selected to connect any combination of the connectors.

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Chamblee, GA, United States of America

Wilton Wayt King