Lower-ladder Was Open Without Inversion Laser Systems Theory

The study of losing without inversion (LWI) is one of the most important and active research front fields in international losing physics nowadays. The study of LWI has not only an important theoretical value, but also wide application prospects. In this paper, we put at first forward a universal model for the open three-level LWI systems, the model is a generalization of the universal model, given by Vladimirov and Mandel, for the closed three-level LWI systems, then studied the nonlinear theory, the dynamics property, the Doppler effect and so on for the Lower-ladder LWI system given by us for the first time.This paper consists of six chapters. In Chapter 1. we explained the significance for studying LWI and the basic principle of producing LWI. introduced simply the current research state and the main contents for the important study subject at present, hi Chapter 2. we put forward an universal model, basing on the universal model of the closed three-level LWI systems, of the open three-level LWI systems, and obtain a general nonlinear analytical solution for the model through a complex calculation. If giving out the detail expression of the matrix describing the incoherent pumping and the population relaxation process of some open or closed three-level LWI system, we can get the nonlinear analytical solution for the corresponding system from the general nonlinear analytical solution. In Chapter 3, we obtained the nonlinear analytical solution of the open Lower-ladder LWI system from the general nonlinear analytical solution for the universal model given in the Chapter 2. then using the numerical calculation results of the analytical solution discussed the effects of the incoherent pumping rate, the ratio of the atomic injection rates, the atomic exit rate, the Rabi frequency of the probe and driving fields and their corresponding detunings on the gain, dispersion and population difference of the system, and got some important conclusions different from those in closed or other open systems. In Chapter 4. we studied the nonlinear dynamics of the open Lower-ladder and V systems, the result showed that, in the resonant case, each system can not only produces pulsed LWI putout through the destabilization induced by the Hopf bifurcation and but also produces continuous LWI putout by the destabilization induced by the Pitchfork bifurcation, and the conclusion is much different from that for the corresponding closed systems. Moreover, we discussed also the effect of the unsaturated gain coefficient, the cavity damping rate, ratio of the atomic injection rates andatomic exit rate on the two instabilities, respectively. In Chapter 5, we mainly discussed the effect of Doppler broadening on the gain, dispersion and the frequency up-conversion of the open Lower-ladder LWI system, got some new conclusions, compared the different and the same between the open and corresponding closed systems. In Chapter 6, we summarized the main and important conclusions obtained in the study of present paper.