Design of Low-Threshold Photonic Crystal Surface-Emitting Lasers

We have investigated the influence of various thicknesses on different layers in GaAs-based photonic crystal surface-emitting lasers (PCSELs), by using the transfer matrix and coupled wave methods to increase the vertically optical confinement factor and to reduce the threshold gain. In addition, the relationship between the threshold gain and the filling factor has been considered. This letter provides an efficient calculation method for designing square-lattice-type PCSEL structures, which shall be useful for the fabrication of low-threshold PCSELs in the near future.