I report on the measurement of threshold energy fluence for optical limiting of nanosecond and microsecond pulses in a high-performance carbon suspension known as Defence Research Establishment Valcartier carbon black suspension (CBS)-100. Thresholds as low as 24-mJ/cm<sup>2</sup> (nanosecond regime) and 100-mJ/cm<sup>2</sup> (microsecond regime) have been obtained. The measurement technique, based on an <i>f</i>/20 optical system and a small analysis aperture, has been tested by measurement of reverse saturable absorber materials and other carbon suspensions whose properties can be found in the technical literature. A factor of merit has emerged from these measurements that could be used to order by limiting performance the different types of carbon suspension. In this ordering, CBS-100 appears as the best choice in the set of suspensions tested for short and long pulses.
© 2001 Optical Society of America
(140.3360) Lasers and laser optics : Laser safety and eye protection
(160.4330) Materials : Nonlinear optical materials
(160.4670) Materials : Optical materials
(190.4400) Nonlinear optics : Nonlinear optics, materials
(230.4320) Optical devices : Nonlinear optical devices
Denis Vincent, "Optical Limiting Threshold in Carbon Suspensions and Reverse Saturable Absorber Materials," Appl. Opt. 40, 6646-6653 (2001)