In this work, we introduce a high-band-gap GaAsP between the barrier layer and the waveguide layer on both sides of the active region to improve the output power and reliability of a semiconductor laser diode. The leakage of carriers in the active region is suppressed, and the device''s performance is greatly improved. Results show that the characteristic temperature of the device increases from 150 to 197.37 K (-75.76 ℃) in the temperature range of 10--40 ℃, and the temperature-dependent drift coefficient of peak wavelength is 0.207 nm/℃. The maximum output power of a 9XX-nm laser diode with a strip width of 200 μm and cavity length of 2000 μm is as high as 14.4 W. The device achieves a maximum electro-optical conversion efficiency of 71.8% for an injection current of 7 A; the slope efficiency is 1.21 W/A. An accelerated aging test of the device at constant current shows that the laser diode has a reliable operating life of over 20000 h.