FDTD Calculation Of The Modes In An Square Microcavity

With development of the information technology, semiconductor laser has applied widely. A section of laser structure is optical-resonator. Unique feature of a resonator is widely attended to optical field distribution that a shape effected and decided. it is used to optical-filter,switcher,optical-modulation and non-linear frequency transformation.This paper have mainly studied and simulated the mode feature of a square resonator. The mode formula of a square resonator is calculated and analyzed by finite-difference time-domain. Maxwell's equation is discrete via central differences in time and space, then numerically solving these equations. Grid analysis of finite-difference time-domain numerical calculation method is a critical core question. But any boundary of a resonator is imperfect, PML boundary condition is introduced for the destination. Acquired information by FDTD is in a time field, but significant factor of a resonator is in a frequency field, so to have introduced intermediate bridge - Fourier transform. Theory analysis is introduced about two dimension Square resonator by Marcatili's approximation method and have obtained field distribution and mode equation. FDTD simulation of Square resonator is studied. Transverse mode figures and vertical mode spectrum of a square resonator is simulated by FullWAVE and have analyzed the mode feature of the resonator. But you'd like to acquired high resolution spectrum, it is important to note the FFTMaxPow2 and FFTMixPow2 used is most efficient when the number of data points is a power of 2. By existing of red green resonant mode and number addition, application of square optical resonator is preferably in the lower mode, performance is slipping by mode heightening. Having obtained numerical result is accurate, and are compared with the FDTD results and shown to be in good agreement. The result is equal the having record. So it is shows that the utility of FullWAVE is very practical, the software is to foreground to appliance of the resonator and waveguide and so on. But any resonator is not perfect, at the end of the paper, prospect and questions about a square is discussed.