All-fiber LP11 mode convertors.
We describe two all-fiber devices for converting light from the fundamental mode to the second-order set of modes in optical fibers. The first is made by controlled hole collapse in a photonic crystal fiber, and the second is a twisted fused coupler made from few-moded conventional fiber. As well as having applications within fiber optics, the devices can be used to generate azimuthally polarized free-space beams.
Witkowska
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A
Department of Physics, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom.
Leon-Saval
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SG
Pham
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A
Birks
T A
TA