Nonlinear analysis of surface-emitting distributed feedback lasers

An analysis of surface-emitting distributed feedback lasers under conditions above threshold is presented. The coupled-wave equations are integrated numerically using a self-consistent technique that includes the effects of gain saturation, carrier diffusion, antiguiding, and free carrier loss. The laser threshold current and slope efficiency are determined as a function of the strip length and p-layer thickness where it is found that the device efficiency can be very high. Antiguiding, which varies when the grating is mistuned with respect to the gain peak, influences the slope, threshold, and shape of the emission far field. Small variations in the longitudinal index of refraction are shown to affect the far-field intensity profile significantly.>