Abstract: In accordance with the invention, an optical router for an optical communications system comprises a pair of transmissive Echelle gratings having their grating surfaces coupled by a waveguide grating. The arrangement provides for substantial design freedom in that the dispersive parameters include the shapes of the first and second Echelle gratings as well as the path length difference among the waveguides. Moreover the device eliminates any need for reflective surfaces in the Echelle gratings.

Abstract: Multiple function bandwidth management systems. Bandwidth-management systems for an optical network are easily assembled by concatenating a plurality of intelligent, miniaturized, bandwidth-management modules (BMM's) together. The BMM's subdivide the wide available spectrum into narrow band segments. Each individual BMM is designed to overcome loss and optimize dispersion, gain, and power or gain equalization for a few channels at a time. Each device includes optical connectors and filters, as well as any other components necessary to direct the band of optical channels through the device's optical path while passing other optical channels within the spectrum to additional devices which can be connected without disturbing existing bandwidth-management modules. Each BMM also includes a digital control module that operates the BMM in any one of a plurality of selectable operating modes.

Abstract: A computer system and method provide a CAD tool by which application specific optical integrated circuits may be easily and quickly designed. The computer system has a graphical user interface which provides the designer with an empty canvas upon which the user may place selected icons of any one of a plurality of optical devices. The designer can select from any one of a number of interconnects to place an icon of the selected interconnect between two of the optical devices. The characteristics of each optical device or interconnect may be varied from default settings to a desired group of settings. To verify the operation of a designed circuit, the user simply clicks each icon along an optical path and the computer system provides a spectral analysis of optical power versus wavelength for the defied optical path. The user can also design optical chips by selecting and placing end ports into an optical circuit and can then clump or group the entire optical circuit into a single icon representing the chip.

Abstract: A computer system and method provide a CAD tool by which a mask for an application specific optical integrated circuit, chip, or wafer may be generated both easily and quickly. The method involves the step of receiving the design for an optical circuit with the circuit design including at least one optical component. Each optical component in the optical circuit is defined by one or more geometric shapes, such as a trapezoid, rectangle, or an arcuate polygon. The method further includes the step of retrieving parameters which define the manufacturing standard by which the optical circuit will be fabricated as well as parameters which define the optical components in the optical circuit. Based on the parameters and the geometric shapes, a plot is generated which forms a mask layout for the optical circuit. The mask layout can then be viewed by a graphical editor whereby a designer can receive visual confirmation that the mask layout accurately portrays the desired optical circuit, chip, or wafer.

Abstract: The present invention includes a system for tracing jumpers used in an exchange to cross-connect optical fibers or wires served by the exchange. The system includes an exchange housing receptacles with optically-encoded data associated with each receptacle or a group of receptacles. The optically-encoded data for a receptacle(s) uniquely identifies the physical location of the receptacle from any other receptacle in the exchange. Likewise, the jumpers each have optically-encoded data formed thereon that uniquely identifies the jumper or jumper end and distinguishes the jumper from any other jumper used in the exchange. If no jumper is to be connected to a particular receptacle, a cover with optically-encoded data can be attached to a receptacle to indicate that no jumper is connected to the receptacle.

Abstract: A ribbon array switch in which an input ribbon array comprising a plurality of input optical fibers can be selectively switched to any one of a plurality of output ribbon arrays mounted on an outer periphery of a switch housing. Preferably, the input ribbon is rotated, whereby the input optical fibers will be optically connected to corresponding output optical fibers that make up the output ribbon arrays. Furthermore, the invention features an optical switch architecture including a first stage comprising a fiber switch element and second stage comprising a ribbon array switch element described above. The output optical fibers of the fiber switch element make up the input ribbon array of the ribbon array switch element.

Abstract: A multimode optical fiber waveguide with graded refractive index for lessening modal dispersion with the gradient produced at least in part by radially decreasing boron oxide content outwardly from the core center within a high silica glass core minimizes modal dispersion by use of a non-parabolic grading function. The optimum gradient for a simple binary borosilicate system for a wavelength of from approximately 0.5 to 1.1 micrometers corresponds with .alpha. = 1.77 .+-. 10 percent in the equation n = n.sub.1 [1-2.DELTA.(r/a).sup..alpha.].sup.1/2, in which n.sub.1 is the axial core index r is the distance from the fiber axis, a is the core radius, .DELTA. is the relative index difference between core center and cladding and .alpha. is a power law exponent which characterizes the profile.

Abstract: Photolithographic techniques are employed to fabricate hemispherical or semicylindrical microlenses on the end surfaces of optical fibers. The power coupling efficiency between junction lasers and fibers is thereby significantly increased.

Abstract: An optical communication network includes at least one single-mode fiber, referred to as a "primary fiber," for transmission between a central office and a distribution node, and at least one multiplicity of single-mode fibers, referred to as "distribution fibers," for transmission between the distribution node and a multiplicity of optical network units (ONUs). Transmissions are exchanged between the primary and distribution fibers via at least one optical coupler located at the distribution node. The network is passive in the sense that all monitoring of the transmission media and the ONUs can be performed at the central office, without active intervention at remote locations. The network includes a monitor and a multiplicity of bypass lines by means of which at least a portion of inbound signals from the distribution fibers are transmitted to the monitor without passing through the optical coupler at the distribution node.