The causation of the generation of strong amplified spontaneous emission(ASE)in the Nd∶YAG slab is analyzed,and the academic and experimental researches on suppressing ASE in high gain laser slab are developed.The pumping duty ratio is 8%,the peak pumping power is 21.38 kW and the injecting intensity of 1064 nm continuous detecting laser is 4 W/cm2.The output power amplifying ratios of the detecting laser are 1.82 and 1.92 respectively with common evanescent coating and multilayer coating.The total stored e...