Research, Based On The Energy Coupling Between The Optical Waveguide By Stimulated Raman Adiabatic Passage Transfer Technology

The energy coupling between different waveguides is a very useful and continuous developmental and new research field, which involves many fields of Optics,Guided Wave Optics, Quantum Mechanics, Informatics, Integrated Optics, Communication Technology and etc. With the development of Laser, nanotechnology, optical fiber and computer, the coupling between different waveguides has been demonstrated from theory to experiment and from experiment to application, In recent years, as the developing of Quantum-Optical analogy methods, the analogy between light energy transfer of coupled waveguides and population transfer of multilevel atomic systems are researched; especially the applications of the stimulated Raman adiabatic passage (STIRAP) technique make the efficiency of the light energy transfer between waveguides improvement,which, meanwhile, becomes a very hot topic. It is a macroscopic physical phenomenon that light energies transfer between waveguides, however,the population transfer among multilevel atomic systems is a microscopic one,thus comparing the energy transfer of coupled waveguides with population transfer of multilevel atomic systems, which is directly associated with macroscopic and microscopic physical phenomenon, meanwhile it gives a good method to research microscopic physical phenomenon by macroscopic technology.This paper, not only to propose the energy transfer of various waveguides system with different coupling coefficient, but also to simulate the energy transfer of various waveguides through design of practical waveguides, provides the good theory for the use of practical waveguides. Because the waveguide coupling is similar to the physical phenomenon of quantum physics, many macroscopic physical phenomenon could be explained well by quantum physics, so the researchment of the paper extended the fields of Quantum-Optical analogies.This paper is mainly composed of three parts, as follow:The part I, we research the wave equation of two curve waveguides through analogy of Landau-Zener tunnelling effect and obtain the time evolution law of mode amplitude with the space by numerical solution when two curve waveguides are coupled. We notice that the waveguides coupling results from the vary of waveguides refractive index. we also found that the energy transfer between waveguides is determined by the coupling coefficient of waveguides, so we could control the energy transfer of waveguides by modulating the coupling coefficient of waveguides. With the analysis of result, we uniquely adopt the Bloch vector to account for the energy transfer, it makes the result more distinct and clearly.The part â…¡, based on three-level population transfer technology-Stimulated Raman adiabatic passage technique, we research the light energy transfer between the boundary waveguides under the adiabatic condition. Firstly, we realized the fully energy transfer of three waveguides by the counterintuitive coupling coefficient, but the middle waveguide is almost never stimulated in the transfer process. Secondly, we realized the energy equal distribution of three waveguides through timely closing the coupled-channel, under the process,the middle waveguides is still never stimulated. We also realized the energy backflow in the first waveguide through extending the coupling between the last waveguides and its adjacent waveguides. Finally, we design the energy transfer of different waveguides with different position by a pair periodic coupling coefficient.In this part,we analyze the energy transfer under different coupling coefficients condition, what's more, we have been simulated the experimental result of energy transfer of waveguides by designing the structure of three waveguides, furthermore, it makes the theory and simulated result identical. The middle waveguides are almost never stimulated in the transfer process, so that it improves the efficiency of energy transfer.The part â…¢, we obtain the spatial evolution law of mode amplitude of array waveguides by using a new method of Lagrange method and get the analytic solutions of mode amplitude under the adiabatic condition. We have researched the full energy transfer from one side of waveguides to another by using a pair delayed coupling coefficient. In this way, we realize the fully energy transfer between the boundary waveguides of the array, but the middle waveguides has little energy in the transfer process, although this energy of middle waveguides are very little and temporary, it still could produce energy loss by radiation, so it has an bad effect on the transfer efficiency. The article not only realized the fully energy transfer between the boundary waveguides, but also all of the middle waveguides never have any energy on the transfer process,by use three coupling coefficient. So that it improved the efficiency of energy transfer. We also detailedly discuss that the effect of the value of refractive index difference of waveguides and medium and the effect of the value of shape of waveguides. In the finally of this part we also researched the energy periodic transfer between boundary waveguides through the modulation of the periodic coupling coefficient.In this part, we have simulated the energy transfer of array waveguides with different coupling coefficient by researching the coupling of waveguides and designing the structure of waveguides, furthermore, it is identical for the theory and simulated result, and also provide the good foundation according to practical application of waveguides. We need to emphasize that in this part we discussed the number of the waveguides array are odd, based on the spatial evolution of array waveguides system and all the issues of energy transfer satisfied the adiabatic condition.