All-optical switching in long-period fiber gratings.

Nonlinear pulse propagation in long-period fiber gratings is studied with a mode-locked Q -switched laser pulse approximately 80ps in duration at a wavelength of 1.05 microm . Optical switching, pulse reshaping, and optical limiting are found at intensities in the range of 1-20 GW/cm(2).

Simultaneous strain and temperature measurement with long-period gratings.

The differential modulation of the attenuation bands in a long-period grating is used for simultaneous sensing of axial strain and temperature. A grating fabricated in a conventional optical fiber is demonstrated for concurrent measurements of strain over a range of 2100 micro? and temperature over a range of 125 degrees C, with maximum errors of 58 micro? and 1 degrees C, respectively.

Broadband fiber dispersion compensation for sub-100-fs pulses with a compression ratio of 300.

We report what is, to our knowledge, the first experimental demonstration of nearly dispersion-free transmission of sub-100-fs pulses over several tens of meters of fiber. 62-fs pulses are broadened initially and recompressed by a ratio of 300 over a 42-m concatenated fiber link consisting of standard single-mode and dispersioncompensating fibers. This dispersion-compensated fiber link is estimated to have a third-order dispersion ~6 times lower than that of dispersion-shifted fiber.

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.

Long-period fiber-grating-based gain equalizers.

Long-period fiber gratings are used to f latten the gain spectrum of erbium-doped fiber amplifiers. A broadband amplifier with <0.2-dB gain variation over 30 nm is presented.