Abstract: Controllable fiber optic attenuators and attenuation systems are disclosed for controllably extracting optical energy from a fiber optic, and therefore attenuating the optical signal being transmitted through the fiber optic. Material removed from a portion of the fiber optic exposes a side surface through which optical energy can be extracted. The portion of the fiber is suspended between two support points, and a controllable material is formed over the surface for controllably extracting optical energy according to a changeable stimulus applied thereto, which affects the refractive index thereof. In one embodiment, the changeable stimulus is light energy from a light source having a different wavelength from the wavelength of the optical energy of interest.

Abstract: Controllable fiber optic attenuators and attenuation systems are disclosed for controllably extracting optical energy from a fiber optic, and therefore attenuating the optical signal being transmitted through the fiber optic. Material removed from a portion of the fiber optic exposes a side surface through which optical energy can be extracted. The portion of the fiber is suspended between two support points, and a controllable material is formed over the surface for controllably extracting optical energy according to a changeable stimulus applied thereto, which affects the refractive index thereof. In one embodiment, the changeable stimulus is light energy from a light source having a different wavelength from the wavelength of the optical energy of interest.

Abstract: Novel polymer compositions for controlling or correcting dispersion mismatch between the composition and a side-fiber polished optical fiber are disclosed. The polymer compositions contain an infrared absorbing dye having an absorption maximum from about 900 to about 1200 nm and a polar olefin copolymer containing monomers which are formed from polar olefins having an ester, benzene, or halogen substitutent attached. A method for controlling the dispersion exhibited by the novel polymer compositions is also disclosed. The method includes forming the polymer composition over an exposed surface of an optical fiber. Dispersion is controlled by controlling the amount of dye present in the polymer composition. Also disclosed is an optical device from which improvements in the uniformity of spectral response and performance are observed across a wavelength band. The optical device includes the polymer composition formed over an optical fiber.

Abstract: Controllable fiber optic attenuators and attenuation systems are disclosed for controllably extracting optical energy from a fiber optic, and therefore attenuating the optical signal being transmitted through the fiber optic. In one aspect, material is removed from a portion of the fiber optic, thereby exposing a surface through which optical energy can be extracted. The portion of the fiber is suspended between two support points, and a controllable material is formed over the surface for controllably extracting optical energy according to a changeable stimulus applied thereto, which affects the refractive index thereof. In one embodiment, the changeable stimulus is temperature, and a controllable heating/cooling source can be provided in the attenuator for control of the attenuation. The limited amount of thermal contact between the suspended, side-polished portion of the fiber optic and the controllable material to surrounding structures offers a more predictable response, and improved response time.

Abstract: Low molecular weight cyclic oligomers of formula (I) ##STR1## in which n is an integer of 2 to 20, and each C in the oligomer is a radical of formula (II): ##STR2## and each X in the oligomer is --O--R--O-- or --S--R--S--, B and D are both carbonyl groups CO, or together represent a divalent radical of formula ##STR3## in which A.sub.1, A.sub.2, A.sub.3 A.sub.4, Ar.sub.1, Ar.sub.2 and Ar.sub.3 are selected from a variety of aromatic radicals, A.sub.1, A.sub.2, Ar.sub.3 and Ar.sub.4 also possibly being hydrogen, are useful in the production of high molecular weight, linear, polyketones, polyphthalazines and polyisoquinolines; the cyclic oligomers have low melt viscosities when heated above their softening temperatures and can be readily molded, whereafter they can be ring-open polymerized to form molded high molecular weight polymer products with excellent properties.

Abstract: Low molecular weight cyclic oligomers of formula (I) ##STR1## in which n is an integer of 2 to 20, and each C in the oligomer is a radical of formula (II): ##STR2## and each X in the oligomer is --O--R--O-- or --S--R--S--, B and D are both carbonyl groups CO, or together represent a divalent radical of formula ##STR3## in which A.sub.1, A.sub.2, A.sub.3 A.sub.4, Ar.sub.1, Ar.sub.2 and Ar.sub.3 are selected from a variety of aromatic radicals, A.sub.1, A.sub.2, Ar.sub.3 and Ar.sub.4 also possibly being hydrogen, are useful in the production of high molecular weight, linear, polyketones, polyphthalazines and polyisoquinolines; the cyclic oligomers have low melt viscosities when heated above their softening temperatures and can be readily molded, whereafter they can be rings-open polymerized to form molded high molecular weight polymer products with excellent properties.