Study On Nonlinear Process Of Quantum Well Based On Resonant Tunneling

Since the laser was born last century, laser technology has been rapidly developed. The study of the nature of light has been expanded from classical optics to quantum optics, nonlinear optics and other fields. So far, people began to study the use of nonlinear optical semiconductor materials.In the nonlinear optic, the Kerr effect and four-wave mixing (FWM) have been attracted tremendous interests and play important roles in Kerr effect for generation of single photons and optical soliton, enhancing the refractive index, and FWM for generation of entanglement of photon pair. Another important application of FWM is all-optical switch, which is considered to be one of the key technology in next-generation all-optical network. Consequently, the study of nonlinear optical effects has potential applications in quantum information processing.From the point of view of practical application, the semiconductor material has an easy choice of materials and a large electric dipole moment and so on. So we extended the study of nonlinear optical processes from atomic system to semiconductor nano structures such as quantum wells (QWs), which have greater practical value. We believe that our study can promote the research and applications based on the quantum properties of semiconductor optical devices. It is well known in the conduction band of the semiconductor QWs structure, the bound electron gas exhibits atom similar characteristics. So the reproduction of atomic medium nonlinear optical effects in semiconductor quantum wells has attracted considerable interests,In this thesis, we designed the appropriate asymmetric double QWs structure and investigated the possibility of enhancing the strength of self-Kerr nonlinearity and the conversion efficiency of FWM based on resonant tunneling. This paper is organized as follows:1. The first part is mainly to explain the basic theory, which can be used to better understand the quantum coherent phenomena such as electromagnetically induced transparency (EIT), coherent population transfer and trapping (CPT), amplification without population inversion (AWI), and the other nonlinear optical effects, for examples, Kerr effect and FWM.2. In this part, we give the semi-classical theory to describe the interaction between light and matter. Picture theory, related approximations, and Schrodinger equations and propagation equations are demonstrated.3. We design an asymmetric quantum wells (QWs) and focus our attention on the tunneling-induced enhancement of self-Kerr nonlinearity. Our results show, with the presence of resonant tunneling, that the self-Kerr nonlinearity can be clearly enhanced, while the absorption of the probe field is very small and can be safely neglected. We attribute the enhancement of self-Kerr nonlinearity mainly to the constructive interference induced by resonant tunneling.4. An asymmetric double QWs structure with resonant tunneling is suggested to achieve highly efficient FWM. We analytically demonstrated that resonant tunneling can induced a highly efficient missing wave in such a semiconductor structure. By modulating the intensities of the control and driving fields, the optimal FWM can be realized.5. My thesis is ended with a summary, and ongoing work is also included.