Patent ID: 7817892

Claim:
A bend insensitive fiber optic cable, comprising: a singlemode fiber; a tight buffer layer surrounding the fiber, wherein a thickest component of the buffer layer has an elastic modulus greater than 515 MPa (75,000 psi); and an outer jacket surrounding the buffer layer, wherein the jacket has a thickness of at least 1.2 mm and an outside diameter of approximately 4.7 mm; wherein the fiber comprises a core and a cladding region for propagating light in a fundamental transverse mode, and the cladding region includes (i) an outer cladding having a refractive index less than the refractive index of the core (n core ), (ii) an annular pedestal region having a refractive index (n ped ) higher than that of the outer cladding and comparable to that of the core, (iii) an annular inner trench region disposed between the core and the pedestal region, the inner trench region having a refractive index (n inner trench ) less than that of the outer cladding, and (iv) an annular outer trench region disposed between the pedestal region and the outer cladding, the outer trench region having a refractive index (n outer trench ) less than that of the outer cladding; and wherein at least one of |n inner trench −n core | and |n outer trench −n core |>0.007; and an interface between the outer cladding and the outer trench region is located at a radial distance of 17 to 23 microns from the center of the core.