tailieunhanh - Báo cáo " Influence of laser parameters on the stationary operation of a two-mode random micro laser "

Solving the system of equations describing the stationary operation of a two-mode random microlaser we have found the transformation of saturated values of mode intensity when laser parameters as gain and loss coefficients as well as field coupling, photon hopping coefficients vary. From obtained results we determined which parameter takes the most important role for stationary operation of random microlasers. | VNU Journal of Science Mathematics - Physics 23 2007 139-142 Influence of laser parameters on the stationary operation of a two-mode random micro laser Dinh Van Hoang Mai Hong Hanh Department of Physics College of Science VNU 334 Nguyen Trai Thanh Xuan Hanoi Vietnam Received 28 May 2007 received in revised form 11 October 2007 Abstract. Solving the system of equations describing the stationary operation of a two-mode random microlaser we have found the transformation of saturated values of mode intensity when laser parameters as gain and loss coefficients as well as field coupling photon hopping coefficients vary. From obtained results we determined which parameter takes the most important role for stationary operation of random microlasers. Keywords Random microlaser field coupling. 1. Introduction The study of random microlaser has been begun since three decades ago. Random lasing has been found in ZnO powder 1 2 in solution of TiO2 nanoparticles in Rhodamine dye in polymethy-methacrylate PMMA or in some polymer systems 3 4 . Recently experiments showed random laser action with sharp lasing peak 5 6 . The explanation of this has been not done yet. There are many theoretical models that were established like John et al 7 combining the electron number equations of energy level with diffusion equation Berger et al 8 using a Monter Carlo simulation and recently Kiang et al 9 combining a FDTD method with the semi classical laser theory 10 . However at present the research on random laser is concentrated to the steady-state properties. Therefore in this paper we examine the stationary operation of two-mode random microlaser. Starting from basic equations for two-mode random microlaser presented in 11 we have solved the basic equations in stationary regime by using numerical method. The obtained results are shown in Section 2. In Section 3 we give the curves describing the influence of laser parameters on the saturated values of mode intensities and Section 4 devoted to