Abstract: A dispersion managed link for transmitting wavelength division multiplexed (WDM) optical signals and method for providing the link are disclosed. The link includes a plurality of spans serially connected by optical amplifiers. Each span includes an optically dispersive fiber connected to a dispersion compensating module (DCM). The fibers and DCMs are selected in accordance with a preferred dispersion map, which represents dispersion along the link, such that points of minimum and maximum dispersion have distributions that change in accordance with one another. The effects of self-phase modulation (SPM), inter-symbol interference (ISI), and cross-phase modulation on the signals are minimized. The preferred dispersion map may be one of ramp type, angular type or arcuate type, and in the case of the latter two, it may have a plurality peaks.

Abstract: An apparatus for determining the angular position of a rotating component having a plurality of angularly spaced magnetic elements is described. The apparatus includes a sensor board and a processor circuit. The sensor board is disposed adjacent to the rotating component and includes a plurality of sensor groups. Each sensor group includes a plurality of magnetic sensors positioned to sense a magnetic field of one of the angularly spaced magnetic elements. Each sensor group generates a multi-state group signal in response to the passage of one of the angularly spaced magnetic elements. The processor circuit communicates with each of the sensor groups and generates position signals in response to the multi-state group signals.

Abstract: Described is a semiconductor laser for generating an optical beam having a stable polarization mode. The laser includes a semiconductor structure having an active layer and a stressor disposed on the surface of the semiconductor structure. Birefringence and gain anisotropy are induced in the semiconductor structure in response to the stress applied by the stressor. The active layer includes one or more quantum wells fabricated to generate an interfacial strain and a desired gain anisotropy. By fabricating the active layer away from the stressor, the gain anisotropy induced by the stressor is substantially reduced. Consequently, the gain anisotropy from the interfacial stress is greater than the gain anisotropy induced by the stressor. The resulting semiconductor structure has a maximum refractive index direction that is parallel to the direction of maximum gain, thus enabling a stable polarization mode for the laser.

Abstract: A reconfigurable apparatus for thermal management of an electronics module is described. The apparatus includes a pair of fans generating airflow along respective fan axes. The apparatus also includes a beat sink having one portion disposed in the airflow of the fans and another portion adapted for thermal coupling with the electronics module. The airflows from the fans are in the same direction when the apparatus is arranged in a front-to-back airflow configuration and the airflows are in opposite directions when the apparatus is arranged in a front-to-front airflow configuration. A removable flow director is included in the apparatus when the apparatus is in the front-to-front airflow configuration to direct the airflow from the first fan towards the second fan.

Abstract: Described is an optical cross-connect switch having substantially reduced polarization dependent loss in comparison to conventional optical cross-connect switches. The switch includes a first mirror array and a second mirror array defining a first array plane and a second array plane, respectively. The first mirror array reflects an array of optical beams received along a first optical axis to be substantially parallel to a second axis. The first array plane defines a pair of axes orthogonal to each of the first and second optical axes. One of the pair of axes is parallel to the first array plane. The second mirror array is positioned to receive the array of optical beams after reflection from the first mirror array such that the other of the pair of axes is parallel to the second array plane.