Three-dimensional emission patterns from flat organic microlasers

We investigate organic solid state microlasers based on a guest-host polymer matrix doped with a lasing dye as gain medium. The polymer layer has a typical thickness of less than 1 μm, and flat cavities of arbitrary shapes can be fabricated with high precision using electron beam lithography. Since the in-plane extension of the cavities with an order of magnitude of 100 μm is much larger than their thickness, they behave like quasi two-dimensional (2D) systems in many respects. Lasing is achieved by the combination of the optically pumped dye and feedback due to reflections at the dielectric cavity boundaries. Many properties of the microlasers can be explained in the framework of a 2D approximation.