  Enhanced polarization conversion in reflection for the Otto and Kretschmann
configurations is introduced as a new method for hybrid-mode spectroscopy.
Polarization conversion in reflection appears when hybrid-modes are excited in
a guiding structure composed of at least one anisotropic media. In contrast to
a dark dip, in this case modes are associated to a peak in the converted
reflectance spectrum, increasing the detection sensitivity and avoiding
confusion with reflection dips associated with other processes as can be
transmission.
