Approximate Analysis of Nonlinear Operation of Square Lattice Photonic Crystal Laser

In this paper, an approximate method for the analysis of 2-D square lattice photonic crystal laser operation above the threshold is presented. Our approach is based on coupled wave equations, including gain saturation effect, and energy theorem. An expression for the small signal gain coefficient as a function of the output power, losses, coupling strength depending on the shape of the primitive cell of photonic crystal as well as index contrast, and active medium dimension is derived. Laser characteristics obtained reveal optimal coupling strength, for given structure parameters, for which maximal power efficiency of the laser structure is obtained.