Optimization algorithm for ultrabroadband multichannel aperiodic fiber Bragg grating filters.

We consider an approach to designing complex multichannel filters for ultrabroadband applications. In contrast to earlier approaches that are restricted to specific problems, our generalized method can be applied to any conceivable fiber Bragg grating (FBG) multichannel design. Our method accommodates hundreds of filter channels that are spaced unevenly in wavelength, with variable widths, depths, and shapes. We demonstrate the power of the method for an FBG design with 150 narrow channels over the region 1400-1800 nm.

Nonlinear dynamics of higher-order solitons near the oscillatory instability threshold.

Nonlinear theory describing the dynamics of solitons in the vicinity of oscillatory instability threshold with a low frequency offset is developed. The theory is tested on the example of parametric degenerate four-wave mixing. All major predictions of our theory are in agreement with the results of direct numerical modeling. This includes the position of oscillatory instability threshold, instability rates, and various instability development scenarios.

Quadratic solitary waves in a counterpropagating quasi-phase-matched configuration.

We demonstrate the possibility of self-trapping of optical beams by use of quasi phase matching in a counterpropagating configuration in quadratic media. We also show the predominant stability of these beams and estimate the power level required for their observation.