The coated laser with a high performance is fabricated based on the InGaSb/AlGaAsSb material system, and simultaneously the laser without facet coating is also fabricated for a performance comparison. The laser without facet coating working in the continuous-wave (CW) mode and under room temperature (RT) shows an output power of up to 300 mW at the injection current of 3.0 A and the maximum wall plug efficiency (WPE) is 8.3%. The laser with facet coating working in the CW mode and also under RT exhibits an output power of up to 380 mW at the injection current of 2.6 A and the maximum WPE is 15.6%. The WPE of the coated laser is always above 10.0% and the emission wavelength is around 2.0 μm at the injection current range of 0.3-2.4 A.