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

We report on the far-field emission characteristics of two-dimensional phot onic crystal-based organic waveguide lasers. The photonic crystals possess square vein, triangular, and honeycomb symmetries. The two-dimensional grat ings are fabricated by employing soft lithographic methods. The far-field p attern 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 p attern 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-pla ne is scattered in the plane of the waveguide. This phenomenon is the photo nic crystal analogue of Kikuchi scattering in electronic crystals. (C) 1999 American Institute of Physics. [S0021- 8979(99)00419-3].