Microscopic imaging along tapered optical fibers by right-angle Rayleigh light scattering in linear and nonlinear regime.

The evolution of the light intensity along an optical waveguide is evaluated by analysing far-field right-angle Rayleigh light scattering. The method is based on point by point spectral mapping distributed along the optical waveguide with a micrometric spatial resolution given by a confocal microscope, a high spectral resolution given by a spectrometer, and a high signal-to-noise ratio given by a highly cooled detector. This non-destructive and non-invasive experimental method allows the observation of the general Rayleigh scattering profile of the optical waveguide in a nominal operation, i.