We review the generation, application and theory of soliton pulses in a nonlinear fiber optic medium
to improve the security and capacity of optical passive systems such as add/drop and PANDA ring
resonators. The improvement of the ring resonator passive systems depends on the output signals,
where the chaotic signal generation within the systems is the critical properties of the output signals
which can be used to enhance the security and capacity. The passive ring resonator systems are
constructed by a nonlinear Kerr effect fiber optic to produce optical signals in the form of chaotic
and multi dark and bright soliton pulses applied in many areas of engineering, biotechnology and
communications. In this research, we review the generation and applications of soliton signals
and theory of the main ring resonator passive systems as add/drop and PANDA ring resonators,
where the easy controlling of the output signals is the benefit of using these systems due to the
interferometric roles.