Simulation Characteristics Of The Half-ring Master Oscillator Power Amplifier

After the semiconductor laser was fist invented in the world, high power, low threshold current and good quality of the light beam are the major goals of the semiconductor lasers. For this purpose, researchers studied lot's of device structures, Master Oscillator Power Amplifier (MOPA) is a good choice of them. The master oscillator of MOPA is usually adopted as Distributed Bragg Reflection Lasers(DBR). DBR lasers have good quality of light beam but the fabrication technology of DBR is complicated.In this letter, we discuss a new structure of MOPAs ,the master oscillator of which is the half-ring laser. The fabrication technology of the half-ring laser is simple. In this letter we analyze the properties with the Poisson equation, the electron and hole rate equations, the Schrodinger equation and the Helmholtz equation in the half-ring laser. This letter presents a self-consistent 1-D single quantum well laser simulation. We have computed the threshold current of the half-ring laser and analyzed the relationship between the curvature radius and the threshold current densities. In order to give a low threshold current density, the curvature radius should be more about 150μm. At the same time, we have computed the Helmholtz equation in the curved waveguides and analyzed the relationship between the curvature radius and the optical field-intensity of the fundamental lateral mode.At last, we compute the optical field-intensity of the Flared Amplifier by the beam propagation method. The field can be propagated using a fast-Fourier-Transform-based routine. Then we analyze the output power and the distribution of the optical field versus the length of the flared amplifier.