Fiber optic sensor for detecting mechanicl quantities

Claim 1

A fiber optic sensor for detecting mechanical quantities comprising light source means; first fiber optic waveguide means, the first end of the first waveguide means being coupled to the light source means, the other end of the first waveguide having a front face ground to a 45° angle relative to the fiber axis, the front face being mirrored; and second fiber optic waveguide means, the first end of the second waveguide means having a front face ground to a 45° angle relative to the fiber axis, the front face being mirrored, and the second end of the second waveguide means being coupled to a photoelement receiver means, wherein the first and second waveguide means are arranged parallel to one another with their respective front faces opposite to one another and closely adjacent, at least one of the waveguide means being movable relative to the other when acted upon by the mechanical quantity so that light transmitted by the light source means travels through the first waveguide means and is received by the second waveguide means at varying intensity levels dependent upon the relative motion of the waveguides, the second waveguide means transmitting the light to the receiver means, the varying light intensity being converted therein to an electrical signal which indicates the magnitude of the motion along or about the fiber axis.