| 主权项 |
1. A bend-compensated LMA optical fiber comprising:
a core region having a longitudinal axis, a refractive index ncore and a radius rcore, a cladding region surrounding said core region, said core and cladding regions configured to support and guide the propagation of signal light in a fundamental transverse mode in said core region in the direction of said axis, said fiber being characterized by a transverse cross-section that is further characterized by a refractive index profile, said cladding region including an inner cladding region surrounding said core region and an outer cladding region having a refractive index nout and surrounding said inner cladding region, wherein said inner cladding region comprises at least a transverse portion in which said index profile is graded with a slope, wherein ncore−nout>0.0010, at least a longitudinal segment of said fiber that, when bent or coiled to a bend radius Rb, said bending or coiling would introduce a change to said index profile within said segment, and at least said longitudinal segment being pre-compensated in that (i) said index profile is approximately azimuthally symmetric with respect to said axis and (ii) the refractive index of at least said transverse portion is configured to compensate for said change. |
