Open AccessMeasuring higher-order modes in a low-loss, hollow-core, photonic-bandgap fiber
Author(s) -
Jeffrey W. Nicholson,
Linli Meng,
John M. Fini,
R.S. Windeler,
A. DeSantolo,
Eric M. Monberg,
F. DiMarcello,
Y. Dulashko,
Muhammad Rosdi Abu Hassan,
R. Ortiz
Publication year - 2012
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.20.020494
Subject(s) - optics , materials science , mode volume , fiber , core (optical fiber) , photonic crystal fiber , transmission (telecommunications) , wavelength , transmission loss , optical fiber , graded index fiber , physics , fiber optic sensor , telecommunications , computer science , composite material
We perform detailed measurements of the higher-order-mode content of a low-loss, hollow-core, photonic-bandgap fiber. Mode content is characterized using Spatially and Spectrally resolved (S2) imaging, revealing a variety of phenomena. Discrete mode scattering to core-guided modes are measured at small relative group-delays. At large group delays a continuum of surface modes and core-guided modes can be observed. The LP11 mode is observed to split into four different group delays with different orientations, with the relative orientations preserved as the mode propagates through the fiber. Cutback measurements allow for quantification of the loss of different individual modes. The behavior of the modes in the low loss region of the fiber is compared to that in a high loss region of the fiber. Finally, a new measurement technique is introduced, the sliding-window Fourier transform of high-resolution transmission spectra of hollow-core fibers, which displays the dependence of HOM content on both wavelength and group delay. This measurement is used to illustrate the HOM content as function of coil diameter.