  High power single mode quantum cascade lasers with a narrow far field are
important for several applications including surgery or military
countermeasure. Existing technologies suffer from drawbacks such as operation
temperature and scalability. In this paper we introduce a fabrication approach
that potentially solves simultaneously these remaining limitations. We
demonstrate and characterize deep etched, buried photonic crystal quantum
cascade lasers emitting around a wavelength of 8.5 {\mu}m. The active region
was dry etched before being regrown with semi-insulating Fe:InP. This
fabrication strategy results in a refractive index contrast of 10% allowing
good photonic mode control, and simultaneously provides good thermal extraction
during operation. Single mode emission with narrow far field pattern and peak
powers up to 0.88 W at 263 K were recorded from the facet of the photonic
crystal laser, and lasing operation was maintained up to room temperature. The
lasing modes emitted from square photonic crystal mesas with a side length of
550{\mu}m, were identified as slow Bloch photonic crystal modes by means of
three-dimensional photonic simulations and measurements.
