Abstract: The present invention provides a system and method for communicating data between network subsystems over optical fibers using a backchannel probe signal. In one embodiment, the present invention includes an optical network having an optical fiber coupled between first and second optical couplers residing in two different subsystems. A first processing unit is coupled to a first tap of the first optical coupler for providing an optical payload signal, and a second processing unit is coupled to a first tap of the second optical coupler for receiving the optical payload signal. A probe signal transmitter is coupled to a second tap of the second optical coupler for providing a probe signal, and a probe signal receiver coupled to a second tap of the first optical coupler for receiving the probe signal. The probe signal may be used to detect erroneous fiber connections or lossy inter-subsystem fibers.

Abstract: A system for use in a bi-directional path switched ring network for detecting a failed optical path and establishing a protection path so as to allow signals from the failed optical path to be re-routed via the protection path is provided. According to one aspect of the system, upon detecting a failure relating to an optical path, the destination node generates a connection request message for transmission to the source node. The connection request message is passed to the source node via one or more intermediate nodes, if any. Each intermediate node examines the connection request message accordingly reserves the requisite wavelength from the protection capacity so as to allow signals from the failed optical path to be re-routed. Upon receiving the connection request message, the source node readies its switching equipment to re-route signals from the failed optical path and generates an acknowledgment message and propagates it back to the destination node via the intermediate nodes.

Abstract: A system for managing signal power levels in an optical network. The optical network comprises a plurality of nodes having logic to receive and transmit optical signals over a plurality of network interconnections. The system includes a method wherein each of the nodes is provided configuration parameters, each of the nodes is configured based on the configuration parameters, power parameter information is exchanged between the nodes, at least some of the nodes are re-configured based on the power parameter information and the steps of exchanging power parameter information and re-configuring at least some of the nodes are repeated until the optical network is fully configured so that the optical signals have selected signal power levels.

Abstract: A cable retainer for organizing, arranging, and routing electrical and optical cable includes a shaft and first and second retention mechanisms. The first retention mechanism, which includes a stop attached at the top of the shaft and a flexible top tap attached to the back of the shaft, is attached to the shaft for restraining the cables within a top retention region. The second retention mechanism, which includes a lip structure attached to the front of the shaft and a flexible side tab extending along each side to the front of the shaft, is attached to the shaft for restraining the cables within side retention regions. This cable retainer can be employed in a cable organizer.

Abstract: A fiber optic switch based on a Mach-Zender type interferometer comprises first and second input optical fibers, first and second intermediate optical fiber segments, and first and second output optical fibers. The switch selectively couples the first and second input fibers either to the first and second output fibers, respectively, or to the second and first output fibers, respectively. To operate the switch, an optical path length of the first intermediate fiber segment is changed, and an optical path length of the second intermediate fiber segment is altered by an equal and opposite amount. Heat is therefore deposited equally in each of the intermediate fiber segments. The intermediate fiber segments lie substantially in a plane, thereby ensuring that the polarization of light traveling through the first intermediate fiber segment does not rotate significantly relative to the polarization of light traveling through the second intermediate fiber segment.

Abstract: An optical switch comprises a two-dimensional array of optical inputs, a Fourier transform lens, and a two-dimensional array of optical outputs. Each of the optical inputs emits an optical beam that is transmitted through the Fourier transform lens to one of the optical outputs. A first deflection means gives each of the optical beams a respective direction of incidence upon the Fourier transform lens. The optical output to which a given beam travels depends on the beam's respective direction of incidence. A second deflection means deflects the optical beams after they have been transmitted through the Fourier transform lens and renders the beams parallel, thereby enabling the beams to couple efficiently to the optical outputs. Each of the deflection means preferably comprises at least one Micro-Electro-Mechanical Systems, or MEMS, deflector array. The optical inputs and outputs preferably comprise optical fibers.

Abstract: Optical systems are corrected for a variety of aberrations by a microlens array where an optical property of the individual microlenses varies as a function of position in the array. For example, the microlenses can be configured so that the focal length varies to correct field curvature. Representative environments for the microlens array may be characterized by a pixellated source (array of individual sources) in an object plane or a pixellated detector (array of individual detectors) in an image plane, or both.

Abstract: An optical system for imaging an array of light sources includes an array of microlenses disposed to intercept light from respective light sources in the array of light sources to reduce the divergence angles of light emanating from the light sources, a first array of lenses (sometimes referred to as minilenses), a second array of lenses (minilenses), and an additional array of microlenses disposed to intercept and focus light from the second array of lenses. Each lens in the first array is sized to intercept light from a respective sub-plurality of the microlenses, and each lens in the second array intercepts and focuses light from a respective lens in the first array. The first and second arrays of minilenses are preferably configured to define a doubly-telecentric imaging system.

Abstract: Techniques for providing normal operation and service restoration capability in the event of failure of terminal equipment or transmission media in a heterogeneous network, such as a hybrid network containing single- and multi-wavelength lightwave communications systems. An optical switching node (OSN) is placed at each node in the ring network to provide the required connections between various fibers and terminal equipment, but having switch states that allow signals on the protection fibers to bypass the terminal equipment at that node. Ring-switched signals propagate around the ring on protection fibers without encountering the terminal equipment at the intervening nodes. To the extent that the protection fiber links between any given pair of nodes are incapable of supporting all the relevant communication regimes, such links are modified to provide such support.

Abstract: A method and apparatus for amplifying an optical signal in an optical network is provided. In an embodiment of the present invention, an optical amplifying module is disclosed for use in an optical network. The optical amplifying module comprises a variable optical attenuator (VOA), an optical amplifier and a controller. The VOA, optical amplifier and controller are coupled to each other and the optical network. The VOA attenuates the optical input signal to produce an attenuated output signal. The optical amplifier amplifies the attenuated output signal to produce an amplified output signal. The controller receives network operating parameters and also monitors the power levels of the attenuated and amplified signals. Based on the measured power levels and the received operating parameters, the controller adjusts the VOA such that the optical output power per channel is maintained at a constant value.