  We design and fabricate large-area (1.1 mm $\times$ 1.1 mm) photonic crystal
quantum cascade lasers, enabling single-mode (wavelength $\sim$ 8.5 $\mu$m)
surface emission at room temperature, with a maximum peak power up to 176 mW.
The beam divergence is $< 1 ^{\circ}$ and without side-lobes. Moreover, by
introducing asymmetry into the photonic crystal pillar shape, a single-lobed
far-field is realized. The photonic band structure is measured with high
spectral (0.72 cm$^{-1}$) and angular (0.1 $^{\circ}$) resolution by using the
photonic crystal quantum cascade laser itself as a detector.
