THE APPROXIMATE EXPRESSIONS OF THE FOUR LAYER ASYMMETRIC WAVEGUIDE CHARACTERISTICS
四层不对称波导的一些近似关系式

In this paper, based on the normalized electronic field and the eigenvalue equation for the four layer asymmetric structure, the approximate expressions of the normalized effective index and the radiation confirement factor were introduced, and the approximate equations for the near field and far field asymmetric Gaussian Profile were deduced.Using the above-mentioned analysis, the dynamic characteristics of the four layer asymmetric waveguide was investigated. From this, the analytic expressions of the injected carrier concentration profile and the gain profile were obtained, and the modal gain, the threshold current density, the optimal active layer thickness, and the optimal threshold current density can be calculated.The calculated results of a series of relation were discussed. We study further the structure parameter effect on the device.