Patent ID: 8705924

Claim:
An optical fiber capable of propagating light having a wavelength, the fiber comprising: a core; an air cladding surrounding the core, the air cladding comprising an air gap having a width; an outer layer surrounding the air cladding; at least one additional layer disposed between said air cladding and said outer layer, wherein said at least one additional layer comprises: (a) a first layer having an index of refraction the same as or lower than an index of refraction of said core and (b) a second layer having an index of refraction lower than the index of refraction of said first layer; and a plurality of webs mechanically coupling the core and the outer layer such that said air gap is disposed therebetween, wherein the fiber is configured to have a numerical aperture greater than about 0.8, and wherein the optical fiber is arranged as a highly non-linear fiber (HNLF), wherein the core diameter is sufficiently small to provide sufficient nonlinearity for super-continuum generation.