Luca Palmieri

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The statistical properties of the random birefringence that affects long single-mode fibers are experimentally evaluated by means of a polarization-sensitive optical time-domain reflectometry. The measurements are in good agreement with theoretical predictions and show, for what we believe is the first time, that the components of the local birefringence(More)
Spun fibers are increasingly used in telecommunication systems because their polarization-mode dispersion (PMD) is lower than that in unspun fibers. In this paper, we investigate the effects of a periodic spin on the PMD of fibers with randomly varying birefringence. Numerical simulations show that when the spin period is of the same order as or larger than(More)
Polarization-mode dispersion (PMD) is a serious impairment for high-bit-rate optical telecommunication systems. It is known that spinning the fiber during the drawing process drastically reduces the PMD. However, the analysis of pulse propagation through a randomly birefringent spun fiber is still at an early stage. In this paper, we derive an analytical(More)
Measurements of birefringence correlation length performed on long single-mode telecommunication fibers are reported. The proposed technique relies on the statistical properties of the backscattered-field polarization, which was measured by means of a polarization-sensitive optical time-domain reflectometer. Experimental results are reported that show good(More)
Experimental results of measurement of the beat length and the differential group delay of several types of long single-mode fiber are presented. The proposed measurement technique is based on a polarization-sensitive analysis of the backscattered signal and allows one to calculate the correlation length of the random birefringence affecting the fiber.
A novel technique, based on polarization-sensitive, frequency-domain reflectometry, for a full noninvasive characterization of spin profile in randomly birefringent spun fibers is presented. Effective measurements of spin profile in a fiber sample a few tens of meters long are reported, but the technique can be straightforwardly scaled to kilometers-long(More)
Spinning is one of the most effective and well-known ways to reduce polarization mode dispersion of optical fibers. In spite of the popularity of spinning, a detailed theory of spin effects is still lacking. We report an analytical expression for the mean differential group delay of a randomly birefringent spun fiber. The result holds for any periodic spin(More)
The dynamics of the fragile glass-forming liquid diglycidyl ether of bisphenol-A was studied by depolarized Rayleigh-Brillouin light-scattering and photon correlation spectroscopy above the glass transition, in the temperature range from 261 to 473 K and in the frequency range from 1 Hz to 300 GHz. The structural (alpha-) relaxation process was revealed and(More)
We consider the two Wai–Menyuk models of birefringence in periodically spun fibers, and we show that the differential group delay differs significantly for the two models when the spin period approaches or exceeds the fiber beat length. When the fiber correlation length is large, we explain this difference quantitatively, and we explain it qualitatively for(More)