Abstract: The present invention provides a method and an FSK/IM receiver to solve the problem of burst-mode detection of frequency modulated labels on an ASK (or IM) payload. In accordance with one embodiment of the present invention, two FSK tones of an input FSK/IM optical signal are separated and communicated to a balanced detector. At the balanced detector, the two FSK tones are subtracted from each other and result in an AC-coupled data stream. The AC-coupled data stream is communicated to a Schmitt-trigger where the hysteresis of the Schmitt-trigger finally eliminates any residual ASK (or IM) payload in the recovered output data. The present invention provides both single channel and WDM solutions.

Abstract: An optical device extracts an information bearing sideband such as an FSK or SCM signal (label) from a composite signal that includes the sideband and an orthogonally modulated signal such as an intensity modulated signal (payload) by splicing the composite signal into a polarization maintaining fiber at a desired angle so that the composite signal is separated into two orthogonal polarizations that experience differential group delay in the fiber. The polarized output signals from the fiber are then coupled to a polarization beam splitter at an equivalent or complementary angle to the desired angle so that one sideband of the composite signal appears at a first output of the beam splitter while another sideband appears at a second output of the beam splitter. The sidebands can then be converted to an electrical data signal by using an appropriate receiver, such as a balanced receiver for FSK signals.

Abstract: The present invention provides a method and an FSK/IM receiver to solve the problem of burst-mode detection of frequency modulated labels on an ASK (or IM) payload. In accordance with one embodiment of the present invention, two FSK tones of an input FSK/IM optical signal are separated and communicated to a balanced detector. At the balanced detector, the two FSK tones are subtracted from each other and result in an AC-coupled data stream. The AC-coupled data stream is communicated to a Schmitt-trigger where the hysteresis of the Schmitt-trigger finally eliminates any residual ASK (or IM) payload in the recovered output data. The present invention provides both single channel and WDM solutions.

Abstract: An optical device extracts an information bearing sideband such as an FSK or SCM signal (label) from a composite signal that includes the sideband and an orthogonally modulated signal such as an intensity modulated signal (payload) by splicing the composite signal into a polarization maintaining fiber at a desired angle so that the composite signal is separated into two orthogonal polarizations that experience differential qroug delay in the fiber. The polarized output signals from the fiber are then coupled to a polarization beam splitter at an equivalent or complementary angle to the desired angle so that one sideband of the composite signal appears at a first output of the beam splitter while another sideband appears at a second output of the beam splitter. The sidebands can then be converted to an electrical data signal by using an appropriate receiver, such as a balanced receiver for FSK signals.