Measurement Of Multipth Interference For Bend Insensitive Fibers: Broadband Source/Osa Technique
We investigated the multipath interference (MPI) characteristics of short length bend insensitive optical fibers using broadband source/OSA technique. It is found that MPI is negligible for fibers with lengths as short as 2 m with worst case splice conditions. As the fiber reaches near or into houses for FTTH applications, it needs to have very high bend resistance . Harsh conditions like sharp turns, staples, and storage with low diameter turns are very common in indoor applications. ITU has recommended a new fiber type called G.657 for these applications  and special bend insensitive fibers (BIFs) are designed for this purpose. As the macro-bend loss of conventional matched clad fibers cannot be reduced beyond certain extent without disturbing mode field diameter (MFD) and dispersion, a trench in cladding design has been proposed. Fibers with trench in cladding design can achieve ultra low bend losses without compromising on MFD and dispersion.