Fig. 1. Experimental setup for high repetition rate acousto-optic gating SAF-LIBS (above) and principle diagram of AOM (below)

Fig. 2. Working time sequence scheme of the experimental setup

Fig. 3. Press tablet sample

Fig. 4. Doublet lines of Al atom at different laser repetition rates

Fig. 5. Linearity of calibration curves by using Al I 396.15 nm

Fig. 6. (a) Temporal evolutions of Al doublet intensity ratio and (b) optimal delay times and SNRs at different fiber collection angles

Fig. 7. (a) Doublet intensity ratio varying with delay times and (b) t_ot values at different aluminum contents

Fig. 8. (a) Calibration curves and predicted results of Al at delay times of 200 ns, 400 ns and 800 ns; (b) comparison of prediction errors of Al under different experimental conditions, the numbers 1-4 here correspond to delay of 200 ns, 400 ns, 800 ns and without AOM, respectively