Broadband optical limiter using carbon-black suspensions in CS/sub 2/

Summary form only given. We have recently shown that the dynamic range of an f/5 optical limiter can be extended by orders of magnitude by using the cascaded-focus geometry. We have tried both reverse saturable absorber (RSA) and carbon black suspension (CBS) materials at a wavelength of 532 nm and found that both can be made to clamp the transmitted energy below eye damage levels for inputs of up to 60 mJ with linear transmittances of 58% and 28%, respectively, and no damage had occurred to the limiter. To determine the wavelength dependence of the CBS, we tested it in the cascaded optical limiter at several wavelengths across the visible. It is obvious that this combination of materials and optical geometry, indeed limits the transmittance near 1 /spl mu/J, for nanosecond pulses of any wavelength, at least within the visible.