Patent ID: 8879878

Claim:
A multimode optical fiber, comprising: a central core surrounded by an outer cladding, said central core having (i) an outer radius R1, (ii) an alpha-index profile, (iii) a maximum refractive index difference Δn1 with respect to said outer cladding; an inner depressed cladding positioned between said central core and said outer cladding, said inner cladding having (i) an outer radius R2, (ii) a width w1 of between about 0.6 micron and 3.5 microns, and (iii) a negative refractive index difference Δn inner with respect to said outer cladding; a depressed trench positioned between said inner depressed cladding and said outer cladding, said buried trench having (i) an outer radius R3, (ii) a width w2, (iii) a negative refractive index difference Δn trench with respect to said outer depressed cladding, and (iv) a volume V trench of between about 1650×10 −3 μm 2 and 4500×10 −3 μm 2 , the volume V trench defined as: V trench = 2 ⁢ π ⁢  ∫ R ⁢ ⁢ 2 R ⁢ ⁢ 3 ⁢ Δ ⁢ ⁢ n trench ⁡ ( r ) ⁢ r ⁢ ⁢ ⅆ r  ; and an outer depressed cladding positioned between said depressed trench and said outer cladding, said outer depressed cladding having (i) an outer radius R4 of between about 30 microns and 47 microns and (ii) a negative refractive index difference Δn2 with respect to said outer cladding.