Opto-mechanical sensors of media outside the fiber

A new concept for the sensing of media outside the cladding boundary of standard unmodified fibers will be presented. Light in the single optical mode is used to stimulate mechanical modes of the entire cladding cross-section. The boundary conditions for the oscillations of the mechanical modes are modified by surrounding substances: the outward dissipation of mechanical waves manifests in faster decay rates. The process is monitored through photoelastic scattering of additional optical probe waves. Point-measurements, spatially distributed analysis, and monitoring of coating layers will be presented.