Lucent Technologies Inc.

Agere Systems Optoelectronics Guardian Corp.

Agere Systems Guardian Corp.

Ephraim Suhir

John David Weld

An optical fiber having a multi-material coating and a fabrication method therefor are disclosed. The coating includes at least two portions adjacent in a longitudinal direction. Adjacent portions are comprised of different materials having different Young's moduli. The invention provides a multi-material coating for an optical fiber and coating fabrication method wherein the interfacial shearing stress for the multi-material coated fiber is less than the interfacial shearing stress for a substantially like fiber coated with only one of the materials found in the multi-material coating. Further disclosed is a telecommunications system and fabrication method, wherein the system comprises multi-material coated fibers having reduced interfacial shearing stress.

Coated optical glass fiber

A method of fabricating a structure comprising an optical fiber interconnect rigidly clamped within an enclosure wherein ends of the interconnect are offset. The method comprises selecting an enclosure material such that its coefficient of thermal expansion leads, during cooling, to a compressive force that minimizes tensile stress in the interconnect. An optical fiber interconnect structure and a semiconductor device fabricated according to the method are also disclosed.

Optical fiber interconnect having offset ends with reduced tensile stress and fabrication method

A bi-material assembly comprising two adherends, adhesively bonded. The assembly is adhesively bonded in an area consisting of a length of 2l at each end of the bonded assembly. The interface of the adherends is not completed bonded so that 2l is less than half of the assembly length. Each bonded area has an inner edge. The inner edge local interfacial shearing stress is substantially equal in magnitude to the inner edge global interfacial shearing stress causing the strength of the bi-material bonded assembly to be substantially the same as a like structure wherein 2l substantially equals half the assembly length. Further are a method of fabricating a bi-material assembly, and a semiconductor device and fabrication method.

Bi-material assembly adhesively bonded at the ends and fabrication method

The present invention is directed to a planar optical waveguide comprising a waveguide core layer interposed between upper and lower cladding layers, characterized in that a so-called &ldquo;effective&rdquo; coefficient of thermal expansion of the layer containing the waveguide core is approximately the same as that of the substrate supporting the optical waveguide.

Strain free planar optical waveguides

Temperature-sensitive devices are mounted within a thermostatic structure that provides temperature compensation by applying compression or tensional forces to stabilize the performance of the device across a significant operating temperature range. In a preferred embodiment, an optical fiber refractive index grating is thermostatically compensated to minimize changes in the reflection wavelength of the grating.

Apparatus and method for thermostatic compensation of temperature sensitive devices

This invention is predicated on applicant's discovery that the conventional polymer coatings are often too thin to prevent buckling and subsequent bending of optical interconnection fiber, and that this buckling and the consequent induced bending can be eliminated by increasing the thickness of the fiber polymer coating. Applicant has further discovered that a thicker coating that might be insufficient to prevent buckling, reduces stress should buckling occur, thereby improving the reliability and quality of the waveguide. The optimal (minimum) polymer thickness for buckling prevention can be calculated in terms of the properties of the fiber and tube materials and the thermal history of the device. Increased thicknesses less than this optimal thickness can nonetheless reduce stress should buckling occur.

Interconnected optical devices having enhanced reliability

Method of improving the performance of optical fiber which is interconnected between two misaligned supports

A method of controlling i.e., minimizing the bowing of the base of an assembly by controlling the location, thickness, and characteristics of the constituent materials used to construct the base.

Device and method of controlling the bowing of a soldered or adhesively bonded assembly

An electronics package consisting of a molded plastic body on a ceramic substrate is provided with a layer of a ceramic surrogate material on a surface of the plastic body opposite the ceramic substrate to reduce bending stress of the package. The coefficient of thermal expansion of the ceramic surrogate layer is less than that of the ceramic substrate. Equations are developed for determining an optimum thickness for the surrogate layer.

Arrangement for reducing bending stress in an electronics package

A method, technique, and apparatus proof test an optical fiber interconnect by applying an ends off-set stress on the optical fiber until the optical fiber fails or breaks, either immediately (short-term strength), or as a result of the delayed-fracture/'static-fatigue' phenomenon for the given off-set, and, hence, for the given stress (long-term strength), imposed for the measured period of time. If, for instance, the short-term strength is addressed, the off-set is measured at the time of the failure, and the corresponding critical strain of the optical fiber is then predicted. In predicting the critical strain, the method and apparatus iteratively determine the total strain, including non-linear components thereof, for an optical fiber interconnect experiencing the measured ends off-set. The analytical model/method includes the steps of iteratively processing characteristic parameters associated with the optical fiber, and determining the non-linear strain associated with the optical fiber. The apparatus includes a processor for implementing the disclosed method.

Method and apparatus for proof testing optical fibers

An electronic assembly having a first component, a second component, and a layer of adhesive bonding the first and second components together, one or both of the first and second components includes thinned or tapered peripheral edges. The layer of adhesive includes a thickened portion which is adjacent to the thinned or tapered peripheral edges, the thickened portion having a thickness which is greater than the thickness of the remaining portion of the layer.

Electronic assembly having improved resistance to delamination

A method for reducing the stress in a fiber by varying the curvature of a fiber disposed on a cylindrical surface, so that the first end of the fiber is clamped to the cylindrical surface and the second end of the fiber is moveably fastened to the cylindrical surface. The method extends the fiber around a portion of the cylinder, provides a fastening element so as to control the location of the second end of the fiber on the cylindrical surface and adjusts the curvature of the fiber so that the total curvature of the fiber remains substantially constant over the entire length of the fiber.

Method for determining and optimizing the curvature of a glass fiber for

Integrated circuits embedded in cards are known in the industry as 'Smart Cards'. The present invention discloses a novel design for housing an integrated circuit(IC) within a card unit. The integrated circuit is first made thin and placed in the midplane of the card. This lessens the tensile stress in the IC when the Smart Card is subjected to bending. In addition, it is suggested that the IC chip is then placed in a relatively long and wide enclosure. This second measure reduces the stress on the IC by compromising between the competing objectives of making a rigid cavity for IC protection, versus making a more compliant cavity for overall card strength. Lastly, the cavity is made out of a material that typically has a Young's modulus that is higher than the Young's modulus of the card but lower than Young's modulus of the integrated circuit. This once again increases Smart Card reliability by utilizing a harder cavity material to protect the IC.

Data carriers having an integrated circuit unit

In accordance with the invention, electronic packages comprising a layer of molded plastic on one side of an insulating substrate are provided with a surrogate layer on the side of the substrate opposite the molded plastic to reduce bending stress. The surrogate layer is preferably thin, has a high coefficient of thermal expansion and is resistant to high tensile stress. Advantageously, the surrogate layer is processed concurrently with the molding of the plastic. Preferred surrogate layers are low temperature thermoplastic sheets, such as acetal plastic sheets, that soften at the molding temperature sufficiently to bond to the substrate. Alternatively, they can be higher temperature rigid materials, such as glass fiber composites, bonded to the substrate with an adhesive layer that cures during molding.

Growing community of inventors

Randolph, NJ, United States of America

Ephraim Suhir