Altug, HVuckovic, J2016-08-162016-08-162016-08-16200510.1063/1.1882755https://infoscience.epfl.ch/handle/20.500.14299/128705We recently proposed two-dimensional coupled photonic crystal microcavity arrays as a route to achieve a slow-group velocity of light (flat band) in all crystal directions. In this letter we present the experimental demonstration of such structures with a measured group velocity below 0.008c and discuss the feasibility of applications such as low-threshold photonic crystal lasers with increased output powers, optical delay components, and sensors. (C) 2005 American Institute of Physics.text::journal::journal article::research article