Abstract: An optical network includes interconnected via an N×N WDM router. The nodes are connected to an optical waveguide ring having a duplex structure. A first set of optical waveguides connects the transmitters in the nodes and a second set of optical waveguides connects the receivers in the nodes. The N×N wavelength router is connected across the ring between the first set of optical waveguides and the second set of optical waveguides. Each of the nodes is able to communicate with any other of the nodes on a respective wavelength channel via the router.

Abstract: A peel-open package includes a polymeric film, a lid adhered to the polymeric film along a continuous portion thereof and a product encapsulated between the polymeric film and lid material. The polymeric film is typically a coextruded multiple layer film having a sealable layer and at least one base layer. The sealable layer comprises an ethylene copolymer derived from at least one monomer selected from the group consisting of vinyl acetate and alkylacrylates, a talc additive, and an additive which provides peelability to the heat seal layer. The lid material is preferably a microporous layer to allow sterilization and prevent subsequent contamination by bacteria and other microbial organisms. The peel-open package provides a good seal range for uncoated Tyvek.RTM., evidence of seal integrity, reduced Tinting, and a seal strength which is sufficiently low to prevent the delaminating or branching of the lid material when it is removed. The present invention also includes methods of making peel-open packages.

Abstract: An optical backplane interconnect comprises a backplane comprising parallel D-fibers (1) that form an optical bus embedded in a plastics substrate (15), which form a coupling with respective parallel D-fibers (23) at an angle .PHI. in a connecting block (21) that is mounted on a card (2). Circuit components on the card are connected by optical fibers (9) to the fibers in the connecting block. The card is held by connections (18, 19), and as the card is pushed into position, coupling means, comprising balls (25, 26) on the connecting block, it self-aligns in groove (27) on the backplane, to set the angle .PHI. between the fibers, to provide a controlled, reliable optical coupling.

Abstract: An optical network includes an erbium-doped silica-based optical fibre having a D-shaped cross-section. The wave-guide carries information signals at 1.53 .mu.m from a signal source and provides amplification to the information signals when pumped by an optical pump source operating at 0.994 .mu.m. Optical signals are tapped from the waveguide by means of evanescent couplers. The waveguide provides amplification to at least partially restore tapping loss to the information signal due to the optical taps. The core of the optical waveguide is chosen to substantially minimize the spot size of signals at the wavelength of the pump source so as to provide preferential extraction of the information signal in order to leave the pump source substantially undisturbed to be able to pump regions of the amplifying waveguide beyond the optical tap.