Optical sensor system

摘要

An optical sensor system is used to sense an effect of external fluid upon propagation of light. The sensor system uses a broadband light source, a broadband light detector and an interferometer. The interferometer has branch comprising a first and second optical filter respectively, each with alternating pass bands and blocking bands as a function of wavelength at wavelength positions defined by optical path lengths of a first and second waveguide in the first and second filter. A shielding layer shield at least part of the first optical path from influence of the fluid and leaves at least part of the second optical path exposed to influence of the fluid.