Thermal lens Z-scan measurements: theoretical and experimental uncertainties for low and high fluorescence quantum yields.

The single-beam -scan thermal lens technique is conducted to evaluate the fluorescence quantum yield of various solutions in the case of high-moderate absorption, considering both scenarios: solutions with substantial fluorescence and solutions with high thermal efficiency but low fluorescence. An analytical calculation is performed to determine the uncertainties associated with the random errors introduced by optical detectors. The results reveal that solutions with low fluorescence lead to a significant error, whereas higher fluorescence can help in decreasing the uncertainty.

Time-Resolved cw Thermal Z-scan for Nanoparticles Scattering Evaluation in Liquid Suspension.

The thermal lens effect is analyzed as a time-resolved Z-scan measurement using cw-single Gaussian beam configuration. The main characteristics of the measurement method are determined. We focus on the evaluation of the measurement error from statistical calculations to also check the linearity of the response and the way to extract the thermo-optical characteristics of absorbing liquids.

Synthesis, Optical, and Morphological Studies of ZnO Powders and Thin Films Fabricated by Wet Chemical Methods.

Zinc oxide nanoparticles were prepared from Zn(CO)(OH) precursor, capped with poly(vinylpyrrolidone) (PVP), and annealed at 600 °C. The obtained powders were characterized by a powder X-ray diffraction (PXD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), UV-visible spectroscopy (UV-vis), Raman spectroscopy, infrared spectroscopy (IR), thermal analysis (TGA/DTA), and third-order nonlinear (NL) optical measurement. Morphological evaluation by TEM and SEM measurements indicated that the precursor micro-particles are ball-shaped structures composed of plates with a thickness of approximately 10 nm.

Measurements of the third- and fifth-order optical nonlinearities of water at 532 nm and 1064 nm using the D4σ method: erratum.

This erratum corrects an error in Fig. 4 of Opt. Lett.

Measurements of the third- and fifth-order optical nonlinearities of water at 532 and 1064 nm using the D4σ method.

The nonlinear response of liquid water was investigated at 1064 and 532 nm using a Nd:YAG laser delivering pulses of 17 ps and its second harmonic. The experiments were performed using the D4σ method combined with the Z-scan technique. Nonlinear refractive indices of third- and fifth-order were determined, as well as the three-photon absorption coefficient, for both wavelengths.

Nonlinear characterization of materials using the D4σ method inside a Z-scan 4f-system.

We show that direct measurement of the beam radius in Z-scan experiments using a CCD camera at the output of a 4f-imaging system allows higher sensitivity and better accuracy than Baryscan. One of the advantages is to be insensitive to pointing instability of pulsed lasers because no hard (physical) aperture is employed as in the usual Z-scan. In addition, the numerical calculations involved here and the measurement of the beam radius are simplified since we do not measure the transmittance through an aperture and it is not subject to mathematical artifacts related to a normalization process, especially when the diffracted light intensity is very low.