Collisions Of Dissipative Optical Bullets And Their Application In All-optical Logic

Optical soliton communication, a novel communication technology, is based on the theory of nonlinear optics and uses optical soliton as information carrier. Soliton maintaining both its amplitude and width at the same time to keep fine long-distance transmission characteristics, has been acknowledged to be the preferential choice for the next generation of ultra-high-speed and large-capacity all optical network. In addition, study of optical soliton have attracted a great number of researchers to involve in because of its wide range of applications, such as in all-optical logic and switching devices, optical data storage, aiding laser cooling by optical trapping of particles and so on. In recent years, with the rapid development of the research, it is recognized that many new optical devices need a set of the balance mechanism between energy loss and energy supplement which is different from solitons in Hamiltonian system. The classic theory for optical solitons needs to be improved and then a new theory for dissipative solitons has come into being. The spatial-temporal soliton in 3D dissipative optical systems usually called dissipative optical bullet (DOB). The DOB is more similar to physical particles than any other solitons in 1D and 2D system and their collision properties make them ideal for building large-scale digital optical switches and optical logic circuits, which is of great significance for its applications in all-optical high-speed communications network and next-generation optical computer. In this paper, we use split step Fourier method to study the collisions between two DOBs in the dissipative system, results are listed below:First, we studied both the head-on and the non-head-on collisions between two stable DOBs to show influence of the geometrical relationship in the initial conditions on the final results. Collision results demonstrated a lot of physical phenomena, including the fusion, fission and quasi-elastic collision characteristics. In addition, some novel and interesting behaviors are contained in our results, in which two or three double bullet complexes occurs, which may arouse a new idea for all-optical switches and logic gates.Second, we studied the energy exchange between DOBs in the collision, showing the importance of the phase relationship in the initial conditions. Extensive simulations reveal that interactions between dissipative optical bullets result in not only energy exchange but also velocities exchange between the DOBs. The general characteristics of energy exchange between bullets in dissipative system are fundamentally same as those in Hamiltonian system, implying that there is the similar mechanism of energy exchange in both systems.Third, we briefly introduced the optical logic gate and gave a feasible analysis of the applications of DOB on the design of all-optical logic at first. Then we present the design philosophy of an all-optical logic based on the collisions between two DOBs and also analyzed advantages and disadvantages of the all-optical logic.