A FABRY-PEROT SENSING ELEMENT BASED ON A LARGE-DIAMETER OPTICAL WAVEGUIDE

摘要

An optical sensing device including a force-applying assembly for providing a force and a Fabry-Perot (FP) element including a large-diameter waveguide having a core and having a cavity in line with the core, the cavity having reflective surfaces and having an optical path length related to the distanc e between the reflective surfaces, the FP element being coupled to the force s o that the optical path length changes according to the force, the FP element for providing an output optical signal containing information about a parameter that relates to the force. Sometimes the large-diameter waveguide is formed by collapsing a glass tube, having a bore and having an outer diamete r of about one millimeter, onto a pair of optical fibers arranged in tandem in the bore and separated by a predetermined distance, and respective end faces of the optical fibers form the cavity and are coated with a wholly or partially reflective material.