Polarization insensitive optical communication device utilizing optical preamplification
AssigneeAmerican Telephone and Telegraph Company, AT&T Bell Laboratories
InventorsMelvyn Dixon, Nils A. Olsson, Robert E. Tench, Liang Tzeng
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Abstract
A polarization insensitive optical device is disclosed which is capable of providing direct optical amplification of an input signal of unknown (and possibly varying) polarization. A polarization diversity technique is utilized wherein a polarization beam splitter is used to divide the incoming signal into orthogonal components of known polarization (TE,TM). The orthogonal components are then separately amplified, using a semiconductor laser as the amplifying device. The amplified components are then recombined, either optically or electrically, to form the final output signal.
Claims14
A polarization insensitive optical communication device for providing optical amplification of an input optical signal comprising an unknown polarization state, said device comprising
- a polarization beam splitter responsive to the input optical signal for directing a first component of said input signal, of a first defined polarization state, along a first signal path and directing a second, orthogonal component of a second defined polarization state, along a second signal path;
- a first semiconductor laser optical amplifier disposed in the first signal path and responsive to the first component for generating as an output an amplified version thereof, the first optical amplifier aligned with respect to the first polarization state of said first component so as to provide maximum amplification;
- a second semiconductor laser optical amplifier disposed in the second signal path and responsive to the second component for generating as an output an amplified version thereof, the second optical amplifier aligned with respect to the second polarization state of said second component so as to provide maximum amplification;
- and
- means responsive to the amplified output signals generated by the first and second semiconductor laser optical amplifiers for combining the amplified first and second orthogonal components to provide as the output of said communication device an amplified version of the optical input signal.
Dependencies are inferred from the claim text.