Optical fiber long-period grating sensors.

We present a novel class of highly sensitive sensors based on long-period fiber gratings that can be implemented with simple and inexpensive demodulation schemes. Temperature, strain, and refractive-index resolutions of 0.65 degrees C, 65.75 micro, and 7.69 x 10(-5), respectively, are demonstrated for gratings fabricated in standard telecommunication fibers.