Abstract

Recently a new design for optical limiters, the bottleneck limiter design, based on strong saturation of excited state absorbers has been discussed. The bottleneck limiter functions by first reaching a state of strong saturation at the exit plane of the nonlinear material. Upon further increase of the incident energy the nonlinear material is progressively driven into strong saturation further upstream from the exit, thus providing further attenuation and a bottlenecking of the output energy. Design considerations lead to a requirement for a characteristic gradient of the concentration of nonlinear absorbers across the sample, or to a varying spacing of discrete plates, to achieve complete saturation and maximum attenuation. In order to test the basic design concept we have performed nonlinear transmission measurements on single and multiple plates of nonlinear absorptive material. In particular, we have attempted to demonstrate that single plates of nonlinear absorbers can be driven into strong saturation and that sequences of multiple plates can be saturated when properly spaced, providing nonlinear attenuation which is given by the product of attenuations of saturated single plates. The proper spacing of the plates provides a scaling of spot sizes so that strong saturation (i.e., F ~ 2.5 F_s) is achieved at plate exit planes and the input fluence for the downstream plates is maintained below the damage fluence (F_d).

© 1994 Optical Society of America