Abstract: A calibration apparatus and method for a polishing machine includes a ferrule surrounding a polishing pad and a plurality of sensors attached to the ferrule. Each of the sensors is directed at a location where optical fibers extending downwardly from a leveling device contact the polishing pad. The sensors are infrared sensors that detect a heat signature generated by friction at the contact point between the optical fibers and the polishing pad as the polishing pad spins and revolves relative to the leveling device. The heat signature that is generated corresponds to the pressure existing between the optical fibers and the polishing pad.

Abstract: In accordance with the present invention, a WDM communication signal including a service channel is received by an add/drop multiplexer. An optical filter element included in the multiplexer separates a first optical payload channel and the service channel from the WDM signal and outputs these signals on a first output port. The remaining WDM channels exit the optical filter at a second output. By utilizing this add/drop multiplexer to select both an optical channel and a service channel, the total power loss associated with a communications network is significantly less than that obtained from networks having separate components to add/drop an optical payload channel and a service channel.

Abstract: A network communication system comprising an optical communication path and a plurality of network elements disposed along the optical communication path. A first network element coupled to the optical communication path includes a first processor and a first optical component. The status of the first optical component being monitored by the first processor. The first processor generates a first electrical signal in accordance with the status of the first optical component. The first network element also includes a service channel transmitter coupled to the first processor and emits a second optical signal to the optical communication path at a second wavelength different than the first plurality of wavelengths in response to the first electrical signal. The second optical signal being modulated in accordance with the second electrical signal.

Abstract: The present invention provides a bidirectional WDM optical communication system with bidirectional optical amplifiers for optically amplifying two counter-propagating WDM optical signals. The bidirectional system includes two sets of optical transmitters for respectively creating a set of west-east optical channels and a set of counter-propagating east-west optical channels. The respective channel sets are multiplexed by optical combiners and output to an optical transmission path. A bidirectional optical amplifier positioned in the optical transmission path amplifies the west-east and east-west WDM signals. In an exemplary embodiment, the amplifier includes at least two optical circulators with at least first, second, and third circulating ports. A gain block interconnects the circulators for optically amplifying the WDM signals. Bragg gratings configured to reflect either the west-east or the east-west channel band are positioned in optical paths which optically communicate with the optical circulators.