| 主权项 |
1. An optical fiber, comprising:
a core and a cladding surrounding the core, wherein the core and cladding have a refractive index profile that is structured to support propagation of a plurality of desired signal-carrying modes, while suppressing undesired modes, wherein the core comprises a portion extending from the center of the core, ncore, to radius a, in which the refractive index decreases linearly from ncore to point a, wherein the cladding comprises a down-doped cladding region abutting or adjacent to the core, and an undoped cladding region abutting the down-doped cladding region, wherein the core, and cladding are configured to support propagation of a spatially multiplexed optical signal comprising a plurality of desired modes, while suppressing undesired modes, wherein the core and surrounding cladding is configured such that undesired modes have respective effective indices that are close to or less than the cladding index so as to result in leaky modes that leak into the outer cladding region, and wherein the index spacing between the desired mode having the lowest effective index and the leaky mode with the highest effective index is sufficiently large so as to substantially prevent coupling therebetween. |
