Lifting polarization degeneracy of modes by fiber design: a platform for polarization-insensitive microbend fiber gratings.
Polarization dependence in microbend gratings is an inherent problem, even in perfectly circular fibers, since antisymmetric modes are almost degenerate linear combinations of four distinct, polarization-sensitive modes. We demonstrate a novel fiber design that lifts polarization degeneracies of the antisymmetric modes to solve this problem. By intentionally exacerbating the polarization splittings, we achieve coupling to only the polarization-insensitive doublet, over wavelength ranges exceeding 100 nm, thus demonstrating a device with practical usable bandwidths. This allows all previous applications envisaged with UV-induced long-period gratings to be realized with the significantly lower-cost microbend technology platform.
Ramachandran
S
S
OFS Laboratories, 600 Mountain Avenue, Murray Hill, New Jersey 07974, USA. sidr@ieee.org
Golowich
S
S
Yan
M F
MF
Monberg
E
E
Dimarcello
F V
FV
Fleming
J
J
Ghalmi
S
S
Wisk
P
P