Understanding Raman-shifting multipeak states in photonic crystal fibers: two convergent approaches.

In this Letter we give theoretical explanations for the recent observations of the excitation of Raman-shifting pulse pairs in solid-core photonic crystal fibers. The formation of these pairs is surprisingly common in the deep anomalous dispersion regime of a large variety of highly nonlinear optical fibers, away from zero group-velocity dispersion points. We have developed two different theoretical models, which agree very well in their conclusions.

Toward the production of micropolarizers by irradiation of composite glasses with silver nanoparticles.

We investigate the possibility of preparation of laser-induced dichroism in composite glasses with a high concentration of silver nanoparticles. A detailed analysis based on the Maxwell-Garnett theory and experimental results shows that particles at different volume fractions react differently to the same laser irradiation parameters. Based on these findings, we demonstrate that a well-defined sequence of multiple irradiation and intermediate annealing can maximize the particles' aspect ratio and avoid unwanted partial destruction.

Manipulation of coherent Stokes light by transient stimulated Raman scattering in gas filled hollow-core PCF.

Transient stimulated Raman scattering is investigated in methane-filled hollow-core photonic crystal fiber. Using frequency-chirped ps-pulses at 1.06 microm as pump and tunable CW-radiation as Stokes seed, the vibrational excitation of the CH(4) molecules can be controlled on the sub T(2) time-scale.

Modeling of optical properties of silver-doped nanocomposite glasses modified by electric-field-assisted dissolution of nanoparticles.

It has been demonstrated recently that silver nanoparticles embedded in a glass matrix can be dissolved by the combination of an intense dc electric field and moderately elevated temperature. In an intermediate state of this process percolated silver layers inside the glass can also occur. These structural modifications significantly modify the optical behavior of the glass, suggesting an interesting perspective for the engineering of optical properties of this kind of metallodielectric materials.

Electric field-assisted formation of percolated silver nanolayers inside glass.

A combination of direct current (d.c.) electric field and moderately elevated temperature is applied to a glass with embedded spherical silver nanoparticles in the near surface region.