coupling between the operating and surface modes and split the degeneracy of
the operating mode, giving rise to PMD.
The wealth of parameters that can be modified to fine-tune the confinement
mechanism in OmniGuide fiber, combined with the virtual absence of material
dispersion, suggest that OmniGuide fiber can be tailored to have certain desir-
able dispersion properties. Engeness et al. [55], for example, describe a simple
modification to the multilayer cladding structure of an OmniGuide fiber to
obtain a dispersion-compensating fiber (DCF) with a theoretical dispersion/
loss figure of merit up to five times larger than conventional DCFs. Similar
design freedom in 2D PCF has also been exploited to provide theoretically high-
performance DCF [56–57]. ...