Optical signal processing

摘要

An optical regenerator for regenerating a multi-level phase encoded signal. A first non-linear medium (HNLF1) generates a comb of frequency harmonics from the signal under the action of a coherent pump, each component bearing the phase encoded data. A filter selects the first and (M−1)th order components. The filtered signal is then input to a second non-linear medium (HNLF2) where a further pump is applied, to coherently add the first and (M−1)th order components and regenerate the signal by reducing phase noise.

主权项

1. An optical device for processing a multi-level phase modulated signal borne on a carrier:
a first pump source operable to generate a first modulation free pump having an offset from the carrier; a first section of non-linear optical material arranged to receive the signal and the first pump, in which the pump and the signal are subject to four-wave mixing to generate a harmonic series of components of the signal separated in wavelength by the offset, the series of components including a first component and a second component; a second pump source operable to generate a second pump relatively coherent with the carrier and first pump, and having an offset from the second component; and a second section of non-linear optical material arranged to receive the first component and the second component as well as the second pump and optionally also the first pump, in which the first and second components are subject to coherent addition, thereby to regenerate the signal.