Analysis of high-reflectivity metal–dielectric mirrors for edge-emitting lasers

A metal–dielectric mirror is shown as a simple solution for high-ref lectivity coatings on cleaved-facet edgeemitting lasers, as well as a means to provide wavelength stabilization and spectral filtering. We show, through the use of a simple SiO₂/Ti/Au coating, ref lectivities better than 90% and a 25% reduction in the 30-dB linewidth of the output spectrum. Wavelength filtering and varying ref lectivities are described as the result of multiple ref lections and a coupled-cavity effect.