Patent ID: 8385704

Claim:
A multimode optical fiber, comprising: a central core surrounded by an outer cladding, said central core having a radius r 1 and a graded-index profile with respect to said outer cladding; an inner cladding positioned between said central core and said outer cladding, said inner cladding having (i) an outer radius r 2 , (ii) a width w 2 , and (iii) a refractive index difference Δn 2 with respect to said outer cladding; and a depressed trench positioned between said inner cladding and said outer cladding, said depressed trench having a refractive index difference Δn t with respect to said outer cladding; wherein said inner cladding's width w 2 and said depressed trench's refractive index difference Δn t satisfy the following inequality: 5.6 1000 × Δ ⁢ ⁢ n t - 2.1 + 2.03 ≤ w 2 .