Patent ID: 8538219

Claim:
An optical fiber comprising: a central glass core region comprising maximum refractive index delta percent Δ 1max , a first inner annular region immediately adjacent to and surrounding said core comprising refractive index delta percent Δ 2 , a depressed annular region surrounding said inner annular region and comprising refractive index delta percent Δ 3 , and a third annular region surrounding the depressed annular region comprising refractive index delta percent Δ 4 ; wherein Δ 1MAX >Δ 4 Δ>Δ 2 >Δ 3 , wherein the difference between Δ 4 and Δ 2 is greater than or equal to 0.01% and a profile volume, V 3 , equal to: V 3 = 2 ⁢ ∫ r ⁢ ⁢ 2 r ⁢ ⁢ 3 ⁢ Δ ⁡ ( r ) ⁢ r ⁢ ⅆ r where r 2 is the inner radius and r 3 is the outer radius of the depressed annular region and wherein |V 3 | is at least 10%-μm 2 , and said fiber exhibits an effective area at 1550 nm which is greater than 110 μm 2 .