Large Deformation In-Fiber Polymer Optical Fiber Sensor

We demonstrate the measurement of the phase shift in a polymethylmethacrylate single-mode optical fiber interferometer, operating at a wavelength of 632.8 nm, up to 15.8% nominal strain in the fiber. The phase-displacement sensitivity is measured to be 1.39 x10 radldrm^-1 for this strain range. This strain range is well beyond the yield strain of the polymer fiber and that previously measured for polymer Bragg gratings and silica optical fiber sensors.