Patent ID: 8792763

Claim:
A multimode optical fiber comprising: a central multimode core region comprising maximum refractive index delta percent Δ 1 , and a radius R 1 ; a cladding comprising an outer radius R clad , the cladding comprising (a) a first inner annular region surrounding said core region and comprising refractive index delta percent Δ 2 , and a radius R 2 , wherein R 2 >R 1 ; (b) a depressed-index annular region surrounding said inner annular region and comprising Δ 3 and a radius R 3 , wherein R 3 >R 2 ; (c) a third annular region comprising refractive index delta percent Δ 4 which is greater than Δ 2 at a radial point less than or equal to 45 microns from the center of the fiber, the third annular region surrounding the depressed annular region; wherein Δ 1MAX >Δ 4 >Δ 2 >Δ 3 , the third annular region being the outermost cladding region with an outer a radius R 4 , wherein R 4 =R clad ; and wherein the difference between Δ 4 and Δ 2 is greater than or equal to 0.03 delta percent.