Engineered Excellence A Journal for Process and Device Engineers Simulation of a DBR Edge Emitting Laser with External Air Gap Tuning Mirror

A methodology for simulating an edge emitting laser is demonstrated that incorporates a distributed Bragg Reflector (DBR) as one of the mirrors, with the other being a variable air gap external planar mirror that is used as a method for fine tuning the lasing wavelength. This type of calculation requires non uniformity of the dielectric’s static and dynamic (pumping) properties in both the transverse and longitudinal directions, together with self consistent coupling to the external tuning cavity. A key challenge addressed is the proper treatment of the open nature of the cavity, such that the amplitudes of the outgoing waves leaving the facets are consistent with the cavity interior and facet reflectivity. Mode competition and hopping are natural consequences of the methodology developed. In the model developed here, the spatial hole burning effects, cross and self-saturation effects can be included while accounting for the degree of spatial overlap of modes. We also account for diffraction losses at the output facet which can become important in the case of strong index guiding