We demonstrate interesting and previously unforeseen properties of a pair of gap solitons in a resonant photonic crystal which can be
predicted and explained in a physically transparent form using both analytical and numerical methods. The most important result is the fact
that we are able to show that the oscillating gap soliton created by the presence of an inversion inside the crystal can be manipulated by
means of a proper choice of bit rate, phase and amplitude modulation. Using this approach, we were able to obtain qualitatively different
regimes of the resonant photonic crystal operation. A noticeable observation is that both the delay time and amplitude difference must exceed
a certain level to ensure effective control over soliton dynamics. The modification of the defect that accomplishes the soliton trapping can
make the dynamics of N soliton trains in the resonant photonic crystal with defects even more interesting and is a subject of the future work.
The dynamical behavior of the nonlinear optical loop mirror (NOLM) with feedback and low birefringence twisted fiber in the loop is examined. It is found that the output of the NOLM with feedback depends on many parameters, including the fiber beat length, the polarization state of the counter-propagating beams in the loop, as well as the length, twist rate, and nonlinearities of the loop fiber. The placement of a quarter-wave plate (QWP) asymmetrically in the loop allows for the tuning of the bistable and chaotic output from the optical resonator. As well, the output polarization state of the NOLM with feedback is shown to rely on the QWP angle as well as the input power, which is of importance when using the NOLM with feedback in optical systems that have polarization sensitivity. As all fibers exhibit some degree of twist and birefringence, the addition of a QWP in the NOLM with feedback allows for an easy and practical measure of control of the bistable and chaotic regions of the nonlinear optical resonator, which is important when implementing the device in an optical system.