Dynamics of 850 nm optical pulses upon compression in a tapered photonic crystal fiber

We consider the optical pulse propagation in a tapered photonic crystal fiber (PCF) wherein dispersion as well as nonlinearity varies along the propagation direction. The generalized nonlinear Schrödinger equation aptly models the pulse propagation in such a PCF. The design of the tapered PCF is based on the analytical results which demand that the dispersion decrease exponentially and the nonlinearity increase exponentially. By employing the self-similar scaling analysis, we have already proposed the efficient pulse compression scheme with the chirped soliton. In order to get more insight into the dynamics of the pulses (the variations in the amplitude, pulse width and chirp) while being compressed, we adopt the generalized projection operator method (POM) which, in turn, helps arrive at two different sets of pulse parameter equations of Lagrangian variation method (LVM) and collective variable method (CVM).