Nikola I. Nikolov

Modulational instability, solitons and beam propagation in spatially nonlocal nonlinear media

We present an overview of recent advances in the understanding of optical beams in nonlinear media with a spatially nonlocal nonlinear response. We discuss the impact of nonlocality on the modulational instability of plane waves, the collapse of finite-size beams, and the formation and interaction of spatial solitons.

Attraction of nonlocal dark optical solitons

We study the formation and interaction of spatial dark optical solitons in materials with a nonlocal nonlinear response. We show that unlike in local materials, where dark solitons typically repel, the nonlocal nonlinearity leads to a long-range attraction and formation of stable bound states of dark solitons.

Improving efficiency of supercontinuum generation in photonic crystal fibers by direct degenerate four-wave-mixing

The efficiency of supercontinuum generation in photonic crystal fibers is significantly improved by designing the dispersion to allow widely separated spectral lines generated by degenerate four-wave-mixing directly from the pump to broaden and merge.

Designing the dispersion for optimum supercontinuum bandwidth using picosecond pulses

Generation of a 800nm wide within 20dB super-continuum with picosecond pulses is possible by proper design of the dispersion to enhance the efficiency of the direct degenerate four-wave-mixing. The robustness to random fluctuations along the fiber is also improved.

Cob-web microstructured fibers optimized for supercontinuum generation with picosecond pulses

Highly nonlinear cob-web microstructured fibers are engineered to have dispersion profiles for efficient direct degenerate four-wave mixing and optimized supercontinuum generation with low-power picosecond pulses. This process is robust to fiber irregularities.