Emission characteristics of two-dimensional organic photonic crystal lasers fabricated by replica molding

Abstract
We report on the far-field emission characteristics of two-dimensional photonic crystal-based organic waveguide lasers. The photonic crystals possess square vein, triangular, and honeycomb symmetries. The two-dimensional gratings are fabricated by employing soft lithographic methods. The far-field pattern that we observe is a result of out-of-plane diffractive coupling of the laser emission generated in the plane of the waveguide. This emission pattern offers a convenient and powerful way to evaluate the nature of laser action in such resonators. In devices which possess defects/breaks in the periodicity of the two-dimensional grating, laser emission generated in-plane is scattered in the plane of the waveguide. This phenomenon is the photonic crystal analogue of Kikuchi scattering in electronic crystals.