Waveguides having patterned, flattened modes

摘要

Field-flattening strands may be added to and arbitrarily positioned within a field-flattening shell to create a waveguide that supports a patterned, flattened mode. Patterning does not alter the effective index or flattened nature of the mode, but does alter the characteristics of other modes. Compared to a telecom fiber, a hexagonal pattern of strands allows for a three-fold increase in the flattened mode's area without reducing the separation between its effective index and that of its bend-coupled mode. Hexagonal strand and shell elements prove to be a reasonable approximation, and, thus, to be of practical benefit vis-à-vis fabrication, to those of circular cross section. Patterned flattened modes offer a new and valuable path to power scaling.

主权项

1. A waveguide that propagates a field-flattened preferred mode, said waveguide comprising:
one or more strands, a shell that surrounds all of said one or more strands, and a cladding that surrounds said shell; wherein said shell comprises a shell refractive index structure configured to induce the field of said preferred mode to have a gradient of zero or nearly zero along the interior perimeter of said shell refractive index structure and to decay with increasing distance in said cladding; and wherein each of said one or more strands comprises a strand refractive index structure configured to induce the field of said preferred mode to have a gradient of zero or nearly zero along the exterior perimeter of said strand refractive index structure and wherein the centroid of at least one of said strands is displaced from the centroid of said shell.