Patent ID: 8639079

Claim:
A multimode optical fiber, comprising: a central core surrounded by an outer optical cladding, said central core having (i) a graded-index profile with respect to said outer optical cladding, (ii) an outer radius r 1 of between about 22 microns and 28 microns, (iii) a maximum refractive index value n 0 , (iv) a minimum refractive index value n cl , and (v) a relative refractive index difference: Δ = n 0 2 - n cl 2 2 ⁢ ⁢ n 0 2 ; an inner cladding positioned between said central core and said outer cladding, said inner cladding having (i) an outer radius r 2 and (ii) a refractive index difference Δn 2 with respect to said outer optical cladding; and a depressed trench positioned between said inner cladding and said outer optical cladding, said depressed trench having (i) an outer radius r 3 , (ii) a refractive index difference Δn 3 with respect to said outer optical cladding, and (iii) a surface integral S 3 : S 3 = ∫ r 2 r 3 ⁢ 1000 ⁢ Δ ⁢ ⁢ n 3 ⁡ ( r ) ⁢ ⁢ ⅆ r ; wherein, expressed as a percentage, the relative refractive index difference Δ is greater than 0.8 percent; wherein said central core's outer radius r 1 , said inner cladding's outer radius r 2 , and said depressed trench's refractive index difference Δn 3 satisfy the following inequality: 0.0115807+0.0127543×( r 2 −r 1 )+0.00241674×1000 Δn 3 −0.00124086×( r 3 −r 2 )×1000 Δn 3 <3.5 percent; and wherein said depressed trench's surface integral S 3 is about −20 microns or less.