Broadband thermal optical limiter

Abstract

The limiting behavior of nigrosin dye dissolved in carbon disulfide was investigated in an f/5 defocusing geometry using 6 ns duration 532 nm laser excitation. Nigrosin dye is a broadband visible light absorber that is used here in conjunction with the large thermal nonlinearity of carbon disulfide solvent to defocus intense incident visible light. A limiting threshold energy of 40 nJ, corresponding to a fluence of only 100 mJ/cm2 in the solution, was observed with device absorption adjusted to 53%.