Periodically nanostructured coatings for spatial filtering and polarization control in microlasers

This work presents the investigation of 2D periodic structures made by conformal deposition of dielectric thin films on the modulated surface, where the deposited layers repeat the primary surface. Depending on the architecture, spatial filtering and polarization control may be performed in transmission or reflection with the incidence of radiation perpendicular to the surface. In the presentation, the overview of different technologies to form conformal coatings on periodically modulated surfaces will be presented. As the proposed 2D photonic structure can be considered a promising component for intracavity spatial filtering, the integration into a microchip laser will be presented. A significant reduction of M2 and brightness increase of two times was recorded for the microchip laser when the fabricated spatial filter was used as one of the resonator mirrors.