Sensitivity optimization of the one beam Z-scan technique and a Z-scan technique immune to nonlinear absorption

Abstract

It is presented a criteria for selecting the optimum aperture radius for the one beam Z-scan technique (OBZT), based on the analysis of the transmittance of the aperture. It is also presented a modification to the OBZT by directly measuring the beam radius in the far field with a rotating disk, which allows to determine simultaneously the non-linear absorptive coefficient and non-linear refractive index, much less sensitive to wave front distortions caused by inhomogeneities of the sample with a negligible loss of signal to noise ratio. It is demonstrated its equivalence to the OBZT.

Techniques for nonlinear optical characterization of materials: a review

“…The authors validated their method by measuring the pump-induced electronic refractive index change in Cr 3+ ions in ruby (Cr 3+ :Al 2 O 3 ) using a CW laser at 532 nm. In pursuing higher sensitivities, the authors of [117] proposed a criterion for selecting the optimum aperture radius for the single-beam Z-scan, and further proposed and demonstrated a modification of the single-beam Z-scan technique based on a direct measurement of the beam width in the far field, which employs a chopper in front of the detector. The results were validated using a CW He-Ne to measure the nonlinearities of Bacteriorodhopsin (BR), and the results agreed with the authors' theoretical development as well as other results for BR known from the literature.…”

Effect of femtosecond laser pulse repetition rate on nonlinear optical properties of organic liquids

“…There have been several attempts to obtain the pure NLO property free from thermal inhibition from intense laser pulses. In recent years, optical chopper and pulse picker are being used to manage the cumulative thermal effect in the optical medium (Gnoli, Razzari & Righini, 2005;Nag, De & Goswami, 2007;Davila Pintle, Lara & Iturbe Castillo, 2013;Edziah et al, 2011;. However, these techniques have their limitations due to their operating principles.…”