Experimental mapping of the spatial and angular emission patterns in photonic crystal microcavities

We report on a set of experimental measurements aimed to fully characterize both the spatial and angular pattern of the optical modes of photonic crystal microcavities. By using a confocal microscope we resolve the spatial distribution of the mode on the sample surface. With the same setup, by introducing an iris placed on a translational stage within the collimated beam region of the confocal microscope, we are able to measure the far field angular pattern of the microcavity modes. The experimental data are compared with theoretical predictions obtained by finite difference in time domain calculations and a very good agreement is found.