At&t Bell Laboratories

American Telephone & Telegraph Co., At&t Bell Laboratories

Robert A Lieberman

Stephen R Forrest

Greg E Blonder

John Burnette MacChesney

Leonard G Cohen

Lee L Blyler

Raymond Wolfe

Richard L Panock

Angelo Anthony Lamola

An optical system, useful as a magnetometer and as a polarization contoller, is disclosed. The system includes a source of electromagnetic radiation, a detector of electromagnetic radiation, and a magnetizable medium via which the source and detector communicate with one another. The system further includes apparatus for forming at least two adjacent magnetic domains separated by at least one domain wall.

Optical systems with thin film polarization rotators and method for

Distributed region optical sensors for chemical detection are provided by utilizing optical fiber technology. A core is provided with a surrounding region that is permeable to the chemical to be detected. A composition whose optical characteristics are altered upon interaction with the chemical to be detected is provided within the permeable material. This change in optical characteristics allows chemical detection through detection of light guided by the fiber.

Optical fiber sensors for chemical detection

A bidirectional fiber optic system is described in which at one terminal the output radiation of a light source (LED or semiconductor laser) is coupled through a small diameter hole in the active area of a photodiode into the core of a larger diameter transmission fiber. On the other hand, radiation propagating through the fiber in the opposite direction exits from the fiber with a large numerical aperture so that most of it is incident on the active area of the photodiode and little is lost through the hole. Also described are a number of photodiode configurations for use in such a system, as well as dual photodiodes to perform both signal detection and output monitoring functions. Further described are fiber optic sensing systems for monitoring such variables as blood pressure.

Bidirectional fiber optic systems

A variable gap device which comprises a suitable material with a cavity formed therein mounted over a body. Elements are formed on the surface of the body and on the top surface of the cavity. In one embodiment, the elements are electrodes of a variable capacitance device, and in another embodiment the elements are partial or total reflectors of incident light from an optical fiber. The surface of the cavity opposite the body is preferably flat and of the order of microns from the body. The device is fabricated by forming a removable layer over a temporary substrate. An appropriate element pattern is formed over the removable layer and the layer is etched in a configuration which will define the cavity. The deformable material is encapsulated over this structure and then removed from the substrate with the element remaining in the cavity. Any removable material remaining in the cavity can then be etched away.

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New Providence, NJ, United States of America

Robert A Lieberman