Fiber Characterization Using Whispering Gallery Modes(Invited)

Fiber whispering gallery modes (WGMs) are surface waves that propagate azimuthally along the outer surface of the fiber cladding. Those waves that are in phase every turn give rise to narrow resonances defined by the resonant wavelength and a high Q factor. The actual values of the resonant wavelengths depend on the radius and the refractive index of the fiber cladding, enabling the development of several fiber characterization techniques. In addition, the typical high Q factor of these resonances (Q > 106) provides the characterization techniques with a low detection limit. Here, we report the development of a technique for measuring temperature profiles along the optical fiber, which enables the characterization of UV-induced absorption loss in photosensitive fibers, and a technique for the measurement of the elasto-optic coefficients and the anisotropy generated by the axial strain in standard fibers.