BEND-INSENSITIVE MULTIMODE OPTICAL FIBER WITH REDUCED IMPACT OF LEAKY MODES

摘要

A multimode optical fiber is provides, which includes an optical core and an optical cladding surrounding the optical core. The optical core has a refractive graded-index profile. The optical cladding includes: an inner layer surrounding the optical core, an intermediate layer, called a “depressed trench”, surrounding the inner layer, and an outer layer surrounding the depressed trench and having a constant refractive index. The depressed trench has a width W and a negative refractive index difference Δnt with respect to the outer layer, and is designed so as to satisfy the following inequality:;|0.585677−114.681×S+13.7287×S2+18.7343×S×W−4.61112×S×Δnt·103−0.913789×W×Δnt·103|+2×W×Δnt·103<−30;wherein: S is the width of the inner cladding, which is included between 0.6 μm and 1.6 μm; Δnt is included between −11.10−3 and −4.10−3; and W×Δnt·103 is lower than −25 μm.

主权项

1. A multimode optical fiber comprising:
an optical core; and an optical cladding surrounding the optical core, the optical core having a refractive graded-index profile, the optical cladding comprising:
an inner layer surrounding said optical core,an intermediate layer, called a “depressed trench”, surrounding said inner layer,an outer layer surrounding said depressed trench and having a constant refractive index, said depressed trench having a width W and a negative refractive index difference Δnt with respect to the outer layer, wherein said depressed trench is arranged so as to satisfy the following inequality:
|0.585677−114.681×S+13.7287×S2+18.7343×S×W−4.61112×S×Δnt·103−0.913789×W×Δnt·103|+2×W×Δnt·103<−30 wherein:S is the width of the inner cladding, which is comprised between 0.6 μm and 1.6 μm;Δnt is comprised between −11.10−3 and −4.10−3; andW×Δnt·103 is lower than −25 μm.