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. InGaAs∕AlGaAs laser layers emitting around 1μm were used for the fabrication of the devices. The laser emits at a single wavelength with a side mode suppression ratio of 50dB. The emission is concentrated in a narrow far field, indicating that a coherent mode is formed over the entire width of the device.