  We present the design and fabrication of photonic crystal structures
exhibiting electromagnetic bands that are flattened in all crystal directions,
i.e., whose frequency variation with wavevector is minimized. Such bands can be
used to reduce group velocity of light propagating in arbitrary crystal
direction, which is of importance for construction of miniaturized tunable
optical delay components, low-threshold photonic crystal lasers, and study of
nonlinear optics phenomena.
