Coaxial optical fiber coupling

Abstract

The main purpose of this work is to demonstrate and physically explain the operation of coaxial directional coupling.Two approaches have been used to explain the behavior of the coaxial couplers. Mode coupling theory and normal mode interference have been successfully employed in the design of such couplers.Experimental observation of switching and beatlength was in agreement with the theory. Such fibers, when designed as couplers are multimoded supporting at least three modes. However, it is possible for such fibers to be single moded.

Conception, Realization, and Characterization of a Very High Negative Chromatic Dispersion Fiber

“…Thus, as expected, in this fiber the spatial distribution of its supermode rapidly changes with wavelength. This behavior differs from what some authors attributed to a somewhat similar structure, namely coaxial fibers, which works like a directional coupler [39]. This difference can be attributed to the fact that the two cores which compose the fiber are highly asymmetric and relatively far away from each other.…”

Pulsed fibre laser with spatial and temporal control

“…The principle of operation of the fibre mode-coupler relies on the wavelength dependence of the field delocalization from the core into the ring at resonant wavelength [6], as illustrated in Figure 1, similar to a fibre fused coupler. At resonant wavelength, the core fundamental mode propagation constant matches that of one of the modes in the ring, and full power transfer is possible between the core and ring mode.…”

Dispersion Effects of Fiber Bending Performed on Microstructured Fiber

“…Coupled mode theory is presented, for example, in [19,20]. In general, bent fiber can theoretically guide two coupling super-modes: the fundamental mode exhibiting negative chromatic dispersion and the cladding mode (practically, it is often a gallery of cladding modes) characterized by positive value of dispersion coefficient.…”