Fiber-optic strain-displacement sensor employing nonlinear buckling.

A new class of intrinsic fiber-optic strain-displacement sensors based on the precisely controlled nonlinear buckling of optical fibers and the resulting optical bend loss is introduced. A multimode fiber version of the sensor is described that exhibits a sensing range convenient for many structural monitoring applications (<100 nm to several millimeters), linear response over a wide range of displacements, and excellent repeatability. It is extremely simple to fabricate and employs inexpensive optoelectronics. A high-temperature version of the sensor is capable of operation at temperatures as high as 600 degrees C.