The a-Si/SiN

x

superlattice was prepared by RFmagnetron reaction sputtering technique and thermal annealing

which made Si nanocrystals appear in the a-Si films.In the experiment

the sample was inserted as saturable absorber into the resonator of Nd:YAG laser.The passive Q-switched operation of 1064 nm laser was achieved when cavity-length was short

and a single pulse waveform of 23 ns-wide was measured.In addition

a single pulse train with average pulse duration of 35 ps was obtained when the cavity-length was set to 124 cm.With the experiment phenomenon and the structure of film

the dynamics of the pulses formation is described;it was mainly ascribed to two-photon saturable absorption and fast relaxation processes of carriers excited in the nano-silicon with quantized states and interface states.The Q-switched output performance in different operating conditions was investigated by the way.