We report on the performance improvement of long-wave infrared quantum cascade lasers (LWIR QCLs) by studying and optimizing the anti-reflection (AR) optical facet coating. Compared to Al2O3 AR coating, the Y2O3 AR coating exhibits higher catastrophic optical mirror damage (COMD) level, and the optical facet coatings of both material systems have no beam steering effect. A 3-mm-long, 9.5-μm-wide buried heterostructure (BH) LWIR QCL of λ ~ 8.5 μm with Y2O3 metallic high-reflection (HR) and AR of ~ 0.2 % reflectivity coating demonstrates a maximum pulsed peak power of 2.19 W at 298 K, which is 149% higher than that of uncoated device. For continuous-wave (CW) operation, by optimizing the reflectivity of the Y2O3 AR coating, the maximum output power reaches 0.73 W, which is 91% higher than the uncoated device.