Lucent Technologies Inc.

Thomas Henry Tiefel, Deceased

Sungho Jin

Wei Zhu

Hareesh Mavoori

Rolando Patricio Espindola

Robert Bruce Van Dover

Paul Joseph Lemaire

David Wilfred Johnson

Debra Anne Fleming

Timothy J Klemmer

The invention is a reconfigurable optical grating device using force from programmable magnets to alter the mechanical strain, preferably a tensile strain, on the gratings so as to induce a latchable change in grating periodicity using a pulse or short-duration current. It includes apparatus for limiting the maximum strain applied to the grating so that the fiber does not fracture, and it provides strain without rotation or twisting of the fiber grating. In preferred embodiment it provides control of magnetic force so as to accurately obtain a predetermined amount of strain and hence wavelength shift in the grating with a minimal amount of electrical power. The inventive structure is useful, e.g. for wavelength division multiplexed optical communication system comprising wavelength channel add/drop devices and/or dynamically gain-equalized amplifiers.

Magnetically reconfigurable optical grating devices and communication

The invention is embodied in an anisotropic, soft magnetic thin film article comprising a cobalt-iron-chromium-nitrogen (Co--Fe--Cr--N) alloy. The thin film is formed such that the alloy has a relatively high saturation magnetization (4.pi.M.sub.s), e.g., greater than approximately 8 kilogauss (kG), a relatively low coercivity (H.sub.c), e.g., less than approximately 2.0 oersteds (Oe), a relatively high squareness ratio (M.sub.r /M.sub.s), e.g., greater than approximately 0.90, and a relatively high anisotropy field (H.sub.k), e.g., greater than approximately 20 Oe, in an as-deposited condition or, alternatively, with a relatively low temperature treatment, e.g., below approximately 300.degree. Celsius. The inventive films are suitable for use in electromagnetic devices, e.g., in microtransformer cores, inductor cores and in magnetic read-write heads.

Article comprising anisotropic Co-Fe-Cr-N soft magnetic thin films

A tunable fiber grating comprises a temperature-sensitive body secured to a fiber having a fiber grating region for transmitting thermally-induced strain to the grating. The amount of strain and hence the degree of wavelength tuning are controlled by adjusting the temperature of the temperature-sensitive body, wherein the extent of adjustment is preferably pre-determined according to feedback from a wavelength detector. Large thermal strains obtainable with the present invention allow a wide range of wavelength tuning with a relatively small and convenient temperature change near ambient temperature. In a preferred embodiment, the temperature-sensitive body is cylindrical and comprised of a nickel-titanium alloy bonded to the grating. In alternative arrangements, the thermal strain effect can be amplified. An add/drop multiplexer employing the tunable gratings is also described.

Device for tuning wavelength response of an optical fiber grating

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North Plainfield, NJ, United States of America

Thomas Henry Tiefel, Deceased