Nonlinear-absorbing fiber array for large-dynamic-range optical limiting application against intense short laser pulses

A complete quantitative description of a nonlinear fiber array for optical limiting application against laser pulses in the picosecond-nanosecond regime is presented. We discuss the dynamics of the molecular photonic processes accompanying the propagation of a laser pulse through the fiber core made of materials that possess reverse saturable absorption, two-photon absorption (TPA), and excited-state absorption (ESA), and we detail the optical limiting effectiveness and limitations of these nonlinear absorption processes individually and in concert. In particular, we demonstrate the importance of excited-state population recycling in extending the dynamic range of the limiting action. Experimental results obtained from a particular fiber core material that possesses TPA and ESA show good agreement with theoretical expectations and demonstrate the optical limiting capability of such a nonlinear fiber array.