The large output power semiconductor optical amplifier with single frequency developed. Output optical power of the amplifier relationship with injection of current is experimentally investigated at different seed laser powers and temperatures. The results of experiments show that the out power with injecting current of 5 A can be up to 1600 mW after injecting the seed laser with power of 30 mW at 1015 nm and the amplification factor is up to 17.3 dB. Moreover, the output power of the amplifier becomes larger as temperature decreases. The output power of semiconductor optical amplifier diode system is very stable once the system reaches thermal equilibrium. Therefore, it can be applied to laser cooling crystals doped with rare earth ions, as well as the optical lattice clock of mercury atoms after frequency quadrupling.