Open AccessCross-correlated (C^2) imaging of fiber and waveguide modes
Author(s) -
Damian N. Schimpf,
Roman Barankov,
Siddharth Ramachandran
Publication year - 2011
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.19.013008
Subject(s) - optics , modal dispersion , interferometry , femtosecond , dispersion (optics) , waveguide , coherence (philosophical gambling strategy) , signal (programming language) , single mode optical fiber , polarization mode dispersion , multi mode optical fiber , optical fiber , modal , physics , fiber laser , dispersion shifted fiber , laser , materials science , fiber optic sensor , computer science , quantum mechanics , polymer chemistry , programming language
We demonstrate a method that enables reconstruction of waveguide or fiber modes without assuming any optical properties of the test waveguide. The optical low-coherence interferometric technique accounts for the impact of dispersion on the cross-correlation signal. This approach reveals modal content even at small intermodal delays, thus providing a universally applicable method for determining the modal weights, profiles, relative group-delays and dispersion of all guided or quasi-guided (leaky) modes. Our current implementation allows us to measure delays on a femtosecond time-scale, mode discrimination down to about - 30 dB, and dispersion values as high as 500 ps/nm/km. We expect this technique to be especially useful in testing fundamental mode operation of multi-mode structures, prevalent in high-power fiber lasers.