Patent ID: 8830448

Claim:
A system for monitoring tightness of stator windings in an electric machine, the system comprising: a light source for providing light at multiple wavelengths; an optical separation sensor situated in a stator core, wherein the optical separation sensor comprises an optical fiber core, an optical fiber cladding enclosing the optical fiber core, and an optical interface element situated in a region of the optical fiber cladding such that a portion of the provided light from the light source is absorbable by the optical interface element, wherein the optical interface element comprises a wavelength selective material configured for higher percentage absorption of the provided light at a first wavelength as compared to percentage absorption of the provided light at a second wavelength; a meter for measuring intensities of the provided light at the first and second wavelengths after absorption by the optical interface element; and a control subsystem for using the measured intensities to assess the tightness of the stator windings.