Abstract: The present invention refers to a device for storing and retrieving one or more binary digits or for increasing persistence time of memory storage for one or more binary digits through Stochastic Resonance, comprising: a. a circuit with at least one bistable element; b. means for introducing an input signal into the circuit; c. means for introducing an adequate amount of noise signal into the circuit and/or means for adjusting the thresholds of the bistable elements and/or means for adjusting the output levels of the bistable elements, whereby the input signal, added to the noise signal, surpasses the transition thresholds, and d. means for detecting the output signal state. The invention is based on the surprising fact that it is possible to store one or more binary digits in a system capable of using existing and inevitable noise in the system advantageously for storage purposes.

Abstract: A method and apparatus for modifying the extinction ratio of a modulated optical signal by adapting a modulator driver signal in response to differences in spectral regions of the modulated optical signal. In another embodiment for modifying the extinction ratio of a modulated optical signal, a modulator signal is adapted in response to differences between a profile of the modulated optical signal and a desired profile.

Abstract: The invention comprises a method and apparatus for passive optical conditioning and format conversion of RZ optical signals including, but not limited to, conversion from RZ to CRZ or to CSRZ, using a nonlinear device. The invention generates signals that may be optimized to improve transmission performance, receiver performance, and/or spectral efficiency of the optical transmission system. A method for passively generating an optical carrier-suppressed return-to-zero (CSRZ) signal according to the present invention includes, propagating an optical RZ signal through a nonlinear element, the nonlinear element configured to broaden the optical RZ signal such that the optical RZ signal is phase shifted by approximately 3Π/2.

Abstract: The invention comprises a method and apparatus for implementing a relatively low cost add/drop multiplexer (OADM) wherein pre-demux and post-mux dispersion compensation is employed in a manner that substantially avoids imparting additional dispersion compensation to pass-through wavelength channels in a WDM system.

Abstract: A method and apparatus for modifying the extinction ratio of a modulated optical signal by adapting a modulator driver signal in response to differences in spectral regions of the modulated optical signal. In another embodiment for modifying the extinction ratio of a modulated optical signal, a modulator signal is adapted in response to differences between a profile of the modulated optical signal and a desired profile.