Optical limiter using multi-walled carbon nanotube suspensions

Optical limiter is the optical component which reduces the laser beam intensity for the protection of eyes and light sensors, and carbon nanotube is known as the highly efficient optical limiting material, recently. However, the effects of heat generated by continuous use were not studied yet. Therefore in this work, the variation of optical limiting effect of the multi-walled carbon nanotube suspensions, in several kinds of solvents such as distilled water, chloroform, ethanol and ethylene glycol, were measured in the range from the room temperature to the degree to the boiling points of each solvents. The pulsed Nd:YAG laser whose wavelength is 1064 nm and pulse duration is 6 ns was used as a light source. The experimental result shows that the limiting efficiencies of all the suspensions were reduced as the temperature increased, and the suspension with a solvent of lower boiling point, viscosity, and surface tension showed high efficiency.