Abstract: A method and system for AO3R functionality is presented. The system includes an AO2R device followed by an AOCR clock recovery module and an AOR retiming device. The AOR retiming device takes as input a recovered clock signal extracted from the output of the AO2R by the AOCR clock recovery module. The output is the recovered clock signal gated by the regenerated and reshaped input signal, and a monitor circuit is used to set the optimum operations of the retiming device. In a first embodiment the output of the AOR retiming device is fed to an AOC code and wavelength conversion output stage, which returns the signal to the NRZ coding, on a service wavelength converted to match the fixed wavelength connection with the DWDM transmission system. In a second embodiment the code conversion is incorporated into the AOR retiming device, and wavelength conversion is accomplished in the AOCR clock recovery device.

Abstract: A method and circuit are presented for the all optical recovery of the clock signal from an arbitrary optical data signal. The method involves two stages. A first stage preprocesses the optical signal by converting a NRZ signal to a PRZ signal, or if the input optical signal is RZ, by merely amplifying it. In a preferred embodiment this stage is implemented via an integrated SOA in each arm of an asymmetric interferometric device. The output of the preprocessing stage is fed to a clock recovery stage, which consists of a symmetric interferometer that locks on to the inherent clock signal by using the second stage input signal to trigger two optical sources to self oscillate at the clock rate. In a preferred embodiment the second stage is implemented via SOAs integrated in the arms of an interferometer, with two DFB lasers as terminuses. The output of the interferometer is an optical clock signal at the clock rate of the original input.