Preparation of optical fibers with non-circular cross-section for fiber lasers and amplifiers

Optical fibers with non-circular cross-sections can be effectively used for pumping of fiber lasers and amplifiers. Non-circular fiber-optic structures can be also employed for a control of propagating light polarization. Details of preparation of three types of optical fibers with non-circular cross-sections are presented. A polarization-maintaining ( PM-) fiber with elliptical core was drawn from non-circular preform to study the effect of drawing temperature onto the fiber geometry. A stabilization of fiber rotation during the drawing was successfully tested during preparation of double-clad ( DC-) optical fibers with hexagonal and special tailored cross-sections. The conservation of original geometry during the drawing was examined.