It is generally used in ODN, divides the power of main stem into empty so as to connect more users.  

FBT coupler uses fusing tapering technology to bound two or more optical fiber altogether, then puts them on the fusion machine to stretch and fusion, and archive the aim of coupling and splitting, finally obtains fiber-optic couplers with different ratios

Applications:                   

LAN

PON

CATV

Optical testing equipment

Optical sensor