Optical waveguides – Polarization without modulation
Patent
1999-05-07
2000-10-03
Ngo, Hung N.
Optical waveguides
Polarization without modulation
385 16, 385 24, 385 37, G02B 628
Patent
active
06128422&
ABSTRACT:
An all-optical polarization splitting switch of the Mach-Zehnder type includes a polarization maintaining fiber, an optical input signal, an optical pump signal, two polarization cross couplers, and a polarization splitting coupler. The polarization maintaining fiber carries the optical signal and the optical pump signal while maintaining polarization orientation. The first polarization cross coupler splits the optical signal into two portions having mutually perpendicular polarization states which have approximately equal power. The optical pump signal, when present, changes the phase of the first portion of the optical signal with respect to the second portion of the optical signal. The second polarization cross coupler combines all the optical power into a combined optical signal. The polarization splitting coupler couples the combined optical signal into a first output port or a second output port in accordance with the polarization state of the combined signal. This configuration eliminates many of the signal phase discrepancies that occur due to thermal instability and unequal fiber lengths which the Mach-Zehnder type switch exhibits. One application for this invention is a polarization splitting switch for a distributed sensor array.
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Ngo Hung N.
The Board of Trustees of the Leland Stanford Junior University
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