Patent ID: 7587110

Claim:
A multicore optical fiber with an integral diffractive element, comprising: a first optical fiber core formed of a non-photosensitive material having an initial index of refraction, the first optical fiber core including; a first longitudinal core axis; a plurality of index-altered portions along the first optical fiber core in a longitudinal direction and having an altered index of refraction different from the initial index of refraction; and a second optical fiber core including a second longitudinal core axis substantially parallel to the first longitudinal axis; wherein: the second optical fiber core has a circular cylindrical shape, a core radius, and another index of refraction which is greater than the initial index of refraction of the first optical fiber core; the first longitudinal axis of the first optical fiber core and the second longitudinal axis of the second optical fiber core are collinear; and the first optical fiber core has an annular cylindrical shape, an inner core radius equal to the core radius of the second optical fiber core, and an outer core radius; and the plurality of index-altered portions are arranged within the non-photosensitive material of the first optical fiber core to form a diffractive structure.