Spectral and spatial single mode emission from a photonic crystal distributed feedback laser

The authors report on the fabrication and characterization of photonic crystal distributed feedback lasers, which are a generalization of distributed feedback and angled distributed feedback lasers. Spectral and spatial mode selection is provided by a two-dimensional, rectangular lattice of etched air holes that is tilted relatively to the cleaved facets. $\mathrm{In}\mathrm{Ga}\mathrm{As}∕\mathrm{Al}\mathrm{Ga}\mathrm{As}$ laser layers emitting around $1\mu \mathrm{m}$ were used for the fabrication of the devices. The laser emits at a single wavelength with a side mode suppression ratio of $50\mathrm{dB}$ . The emission is concentrated in a narrow far field, indicating that a coherent mode is formed over the entire width of the device.