Tuned-port twin biconical-taper fiber splitters: fabrication from dissimilar low-mode-number fibers

Fused biconical-fiber splitters have been fabricated from dissimilar low-mode-number optical fibers. Through selective etching of the cladding diameters of the two fibers forming the splitter, the amount of energy transferred between the fibers can be controlled. A tuned condition characterized by low insertion loss and strong optical coupling between modes of the fibers forming the splitter has been demonstrated. In the detuned condition an asymmetry in the coupling between fibers has been observed.