SELF-ALIGNING OPTICAL FIBER AND FIBER-RING OPTICAL RESONATOR USING SAME

A continuously drawn optical fiber comprising a core and cladding having different refractive indices and forming a single-mode guiding region, and the outer surface of the fiber having a cross-section forming a pair of orthogonal exterior flat surfaces so that the location of the guiding region can be ascertained from the exterior geometry of the fiber, the guiding region being offset from the center of gravity of the transverse cross-section of the fiber and located sufficiently close to at least one of the flat surfaces to allow coupling to a guided wave through that surface by exposure or expansion of the field of the guiding region.