Mode-profile dependence of the electrostrictive response in fibers

Particle swarm optimization on threshold exponential gain of stimulated Brillouin scattering in single mode fibers

We implement a particle swarm optimization (PSO) algorithm to characterize stimulated Brillouin scattering phenomena in optical fibers. The explicit and strong dependence of the threshold exponential gain on the numerical aperture, the pump laser wavelength and the optical loss coefficient are presented. The proposed PSO model is also evaluated with the localized, nonfluctuating source model and the distributed (non-localized) fluctuating source model. Using our model, for fiber lengths from 1 km to 29 km, the calculated threshold exponential gain of stimulated Brillouin scattering is gradually decreased from 17.4 to 14.6 respectively. The theoretical results of Brillouin threshold power predicted by the proposed PSO model show a good agreement with the experimental results for different fiber lengths from 1 km to 12 km.

Bulk and surface laser damage of silica by picosecond and nanosecond pulses at 1064 nm

We measured bulk and surface dielectric breakdown thresholds of pure silica for 14 ps and 8 ns pulses of 1064 nm light. The thresholds are sharp and reproducible. For the 8 ns pulses the bulk threshold irradiance is 4.75 +/- 0.25 kW/microm2. The threshold is approximately three times higher for 14 ps pulses. For 8 ns pulses the input surface damage threshold can be made equal to the bulk threshold by applying an alumina or silica surface polish.

Electrostrictive response in single-mode ring-index-profile fibers

We have theoretically investigated, for what is to our knowledge the first time, the electrostrictive response in a single-mode ring-core fiber. We found that the electrostrictive response function differs strongly from those of standard fibers with a Gaussian light-intensity profile.