Effects of optical limiting properties of suspended carbon nanotubes by multi-pulse laser

Effects of repetition frequency on optical limiting properties of suspended carbon nanotubes irradiated by an 8 ns 532 nm laser was investigated in the experiment. Optical limiting properties of suspended carbon nanotubes(10~20 nm) with incident laser beam at 1 Hz, 3 Hz, 5 Hz, 10 Hz repetition frequency were analyzed, and optical limiting effects of suspended carbon nanotubes irradiated by laser beams focused by different focal lenses were compared, and the limiting threshold of suspended carbon nantotubes at incident laser beam with different repetition frequency was quantitatively described. The experimental results indicate that suspended carbon nantobutes has good optical limiting response to 532 nm laser at different repetition frequency, and optical limiting thresholds with incident laser beam of 5 Hz and 10 Hz repetition frequency are much nearly two and three times lower than signal incident laser pulse, respectively. And the experimental results also indicate that the suspended carbon nanotubes has better optical limiting response in the tight focus system than in the general focus system.