Abstract: The present invention relates to a surface interaction type multimode optical fiber coupler. A representative embodiment of the present invention comprises a plurality of optical fibers with each having an expanded core section. The expanded core sections of the optical fibers are fused together forming a fused section. Each of the optical fibers is optically coupled with at least one other optical fiber primarily through surface interaction in the fused section. The optical fibers are suitable for multimode operations. According to an embodiment of the present invention, a method of fabrication an optical fiber coupler comprises: providing a plurality of optical fibers with each having an expanded core section; and maintaining at least a portion of the expanded core sections in contact and simultaneously heating at least a portion of the expanded core sections that are in contact to form a fused section until a predetermined end condition is reached.

Abstract: A network architecture for use in a data traffic network that includes a plurality of nodes and a plurality of data links coupling the nodes. The network architecture includes a working data link(220) that forms a signal pathway between a first router (200) and a second router (210) within the network. A protection data link(255) is likewise provided and forms a second signal pathway. The routers (200, 210) include both working data ports (312) and protection data ports (314) with each port including associated transmit and receive terminals. A combination of line splitting devices (250), line selection devices (260) and switch arrays (430, 435) are used to switch the flow of traffic data from the working data link (220) to the protection data link (255) or a protection channel (450) as is appropriate.

Abstract: A tunable optical fiber grating package with a supporting assembly and an optical fiber portion having at least one grating between a first end and a second end of the fiber portion is provided. The first end and the second end of the fiber portion define a longitudinal direction and the at least one grating has an optical characteristic that varies with strain of the fiber portion. The supporting assembly has a first supporting member formed of a material having ultra low CTE, a second supporting member formed of a material having a negative CTE and a tuning means for changing the dimension of the first supporting member substantially along the longitudinal direction. The first supporting member and the second supporting member are bonded together.

Abstract: A method of fabricating multiple superimposed Bragg gratings in the core of a portion of a photosensitive fiber is provided where only one common phase-mask is used. The multiple superimposed Bragg gratings are inscribed in the portion of the photosensitive fiber by applying different predetermined longitudinal stresses to the portion for each corresponding writing. The different predetermined longitudinal stresses are applied to the portion of the photosensitive fiber by stretching the portion along its longitudinal axis bi-directionally and simultaneously such that the centers of all fiber Bragg gratings imprinted in the portion are substantially superimposed at the center of the portion of the photosensitive fiber.

Abstract: A method of fabricating multiple superimposed Bragg gratings in the core of a portion of a photosensitive fiber is provided where only one common phase-mask is used. The multiple superimposed Bragg gratings are inscribed in the portion of the photosensitive fiber by applying different predetermined longitudinal stresses to the portion for each corresponding writing. The different predetermined longitudinal stresses are applied to the portion of the photosensitive fiber by stretching the portion along its longitudinal axis bi-directionally and simultaneously such that the centers of all fiber Bragg gratings imprinted in the portion are substantially superimposed at the center of the portion of the photosensitive fiber.

Abstract: A tunable optical fiber grating package with a supporting assembly and an optical fiber portion having at least one grating between a first end and a second end of the fiber portion is provided. The first end and the second end of the fiber portion define a longitudinal direction and the at least one grating has an optical characteristic that varies with strain of the fiber portion. The supporting assembly has a first supporting member formed of a material having ultra low CTE, a second supporting member formed of a material having a negative CTE and a tuning means for changing the dimension of the first supporting member substantially along the longitudinal direction. The first supporting member and the second supporting member are bonded together.