Abstract: Cationic radial catenane comprising a central cationic ring and two or more radial cationic rings mechanically interlocked central cationic ring and methods for making the same are disclosed herein.

Abstract: Cationic radial catenane comprising a central cationic ring and two or more radial cationic rings mechanically interlocked central cationic ring and methods for making the same are disclosed herein.

Abstract: An apparatus and method are provided for monitoring the Q-factor of a plurality of main signals that are simultaneously transmitted across a fiber optic line using wave division multiplexing. In particular, the includes an optical tap, a tunable optical bandpass filter, and a Q-detection circuit. The optical tap operates to tap the fiber optic line to provide a plurality of tapped signals corresponding to the plurality of main signals. The tunable optical bandpass filter acts to select one of the plurality of tapped signals, by only passing a selected signal in a chosen channel frequency band. The Q-detection circuit then determines the Q-factor of the selected signal. This operation can be performed sequentially for each of the plurality of tapped signals to provide a measure of the Q-factor for each of the plurality of main signals. This operation can also be continually repeated to provide a constant measurement of the Q-factor of each of the plurality of main signals.

Abstract: A testing circuit is provided for determining the Q-factor of an optical communication system. In the testing circuit, a variable attenuator attenuates a received optical signal in response to an attenuator control signal. A first optical-to-electrical converter converts a first portion of the attenuated optical signal into an electrical data signal. A second optical-to-electrical converter converts a second portion of the attenuated optical signal into a first power indication signal. A decision circuit detects high and low data bits in the electrical data signal based on a plurality of threshold voltage signals, and provides decision signals indicative of the results of these determinations. An error monitoring circuit receives the decision signals, determines the bit error rate of the incoming optical signal for the plurality of threshold voltages, and provides bit error rate signals.