EFFECTS OF MULTIPLE INTERNAL SAMPLE REFLECTIONS ON NONLINEAR REFRACTIVE Z-SCAN MEASUREMENTS

The effects that multiple internal sample reflections can have on Z-scan and eclipsed Z-scan measurements are investigated. The sample is treated as a combination of a nonlinear lens and an etalon. Under steady-state conditions with thin-lens and mean-field approximations, an ABCD analysis is used to model the self-focusing and self-tuning effects of the beam and to determine the far-field transmittance of a beam in such experiments through an aperture or around an obscurant. The effects that result from such a treatment include a simulation of nonlinear absorption, amplification of transmittance signatures, and strong distortions of signatures in regimes of optical switching and bistability.