Cross-correlated (C-2) imaging of fiber and waveguide modes

Photonics Center, Department of Electrical and Computer Engineering, Boston University, Boston, MA 02215, USA.
Optics Express (Impact Factor: 3.53). 07/2011; 19(14):13008-19. DOI: 10.1364/OE.19.013008
Source: PubMed

ABSTRACT 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.

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Available from: Damian N Schimpf, Jul 01, 2015