One-step extrusion of core/clad preform for tellurite glass optical fiber fabrication

This paper describes the direct fabrication of a step-index tellurite glass preform using a novel extrusion technique of simultaneously forcing, in one step, core and clad glasses through a die with a sophisticated inner design. The fiber drawn from the extruded preform demonstrated a loss of ∼1.4 dB/m at 1.32 µm, which is comparable to the existing two-step direct extrusion methods. The new extrusion technique shows promise for the direct fabrication of soft glass preforms with a low and uniform core/clad ratio, which can be drawn into fibers with high interface quality and low loss.