Resonant optical cavity light emitting devices and method of producing such devices are disclosed. The device includes a substrate, a first spacer region, a light emitting region, a second spacer region, and a reflector. The light emitting region is configured to emit a target emission deep ultraviolet wavelength, and is positioned at a separation distance from the reflector. The reflector has a metal composition comprising elemental aluminum. Using a three-dimensional electromagnetic spatial and temporal simulator, it is determined if an emission output at an exit plane relative to the substrate meets a predetermined criterion. The light emitting region is placed at a final separation distance from the reflector, where the final separation distance results in the predetermined criterion being met.