A method for the fabrication of a fiber optic coupler includes a step of fusing together two optical fibers along their longitudinal sections by heating them and a step of stretching the two optical fibers independently of one another with different conditions of tension and/or. A method for the fabrication of a fiber optic coupler includes a step of fusing together two optical fibers along their longitudinal sections by heating them and a step of stretching the two optical fibers independently of one another with different conditions of tension and/or. A method for the fabrication of a fiber optic coupler includes a step of fusing together two optical fibers along their longitudinal sections by heating them and a step of stretching the two optical fibers independently of one another with different conditions of tension and/or temperature so that. What is a Fiber Coupler? Fiber couplers belong to the basic components of many fiber-optic setups. Note that the term fiber coupler is used with two different meanings: It can be an optical fiber device with one or more input fibers and one or more output fibers. Light from an input fiber can. Fused Bionical Taper (FBT) technology remains a cornerstone in passive optical network (PON) component manufacturing, particularly for fiber optic couplers, splitters, and WDM devices. The fabrication process and the performance parameters of these devices are reviewed.