Patent ID: 7869713

Claim:
A multiplexer for performing Add/Drop operations on an Optical Time Division Multiplexed (OTDM) optical signal, the multiplexer comprising: an input configured to receive an OTDM optical signal having a wavelength of λ d ; an extractor configured to extract a selected channel from the OTDM signal received at the input and to clean the OTDM signal of the selected channel, the extractor comprising: an optical generator configured to generate optical impulses synchronized with the selected channel; a Semiconductor Optical Amplifier (SOA) configured to receive the OTDM signal and the synchronized optical impulses and having an output; an extractor band-pass filter connected to the SOA output, the extractor filter having a pass band around a wavelength λ c that is outside the wavelength λ d of the received OTDM signal; a cleaner band-pass filter connected to the SOA output, the cleaner filter having a pass band around the wavelength λ d ; wherein the wavelengths of the generated optical impulses are selected so as to generate Four-Wave-Mixing (FWM) effects, Cross-Phase-Modulation (XPM) effects, and Cross-Gain-Modulation (XGM) effects at the SOA to shift the selected channel signal to the wavelength λ c such that the extractor band-pass filter outputs a signal to be extracted from the selected channel, and such that the cleaner band-pass filter removes from the OTDM signal the signal to be extracted, and outputs a cleaned OTDM signal; wherein the optical generator comprises: a first source configured to generate the optical impulses with a frequency that is equal to a frequency of repetition of a channel in the received OTDM signal; and a polarized laser having an emission that is combined with delayed impulses output by the first source so as to produce optical impulses with two co-polarized pumps, and wherein the effects in the SOA are substantially independent of a polarization of the incoming OTDM signal.