# numerical modeling

## Parametric Gain Calculation in Photonic Crystal Fiber

Signal wave parametric gain was calculated in photonic crystal optical fiber. Photonic crystal fiber structure was optimized for broadband parametric gain. It is shown, that gain bandwidth for photonic-crystal fiber optical parametric amplifier could be more than 400 nm. Spectral changings in parametric gain due to modulation of photonic crystal waveguide cross-section was studied.

## Optical Soliton Inelastic Interacitons in Nonlinear Schrödinger Equation with Variable Coefficients Model

It is shown that in systems described by nonlinear Schrödinger equation with variable coefficients, interaction of two solitons can carry an inelastic character. Inelastic collision solitons can lead to changes in their group velocities, amplitudes and durations. We consider some particular cases related to the separation of the soliton pair and formation of a bound state of two solitons. In the applied aspect these phenomena can be used to control the soliton interaction in optical fiber communications.

## Dispersion Characteristic Calculation of Photonic Crystal Fiber Guided Modes

Dispersion characteristic of photonic crystal fiber guided mode is calculated. Numerical modeling based on the Maxwell equation for magnetic components for field of the photonic crystal is obtained. It is shown, that slot photonics crystal waveguides can be used to tailor dispersion.