We report a single-beam, differential z-scan technique with improved sensitivity for the determination of nonlinear absorption and refraction of materials. A sample is scanned in the direction of beam propagation as usual, but, in addition, its longitudinal position is dithered, producing a detector signal proportional to the spatial derivative of only the nonlinear transmission and therefore g...

Cooperative, or energy-transfer, upconversion reduces the population of the I13/2 manifold in Er:YAG, increasing the laser threshold, but not, in theory, the slope efficiency [1]. We have measured the cooperative upconversion parameter in Er:YAG using the z-scan technique as a function of Er concentration (0.5% to 5%) with the sample at room temperature (298 K) and 80 K. The value we obtain at ...

An analytical expression for the Z-scan signal from two-level atoms which show a saturable dispersive and absorptive nonlinearity is derived. An approximate solution is obtained for the normalized transmittance and compared with numerical calculations. 2004 Elsevier B.V. All rights reserved.

We present an experimental study of Z-scan measurements of the nonlinear response of cold Cs atoms in a magneto-optical trap. Numerical simulations of the Z-scan signal accounting for the nonuniform atomic density agree with experimental results at large probe beam detunings. At small probe detunings a spatially varying radiation force modifies the Z-scan signal. We also show that the measured ...

We analyze the z-scan experiment with anisotropic Gaussian Schell-model (AGSM) beams. The expression for the cross-spectral density of the AGSM beam passing through the lens and onto the nonlinear thin sample is derived. Based on the expression, we simulate the results of the z-scan experiment theoretically and analyze the effects of the e factor (e=w(0x)/w(0y)) and the spatial degree of cohere...

This paper describes a new perspective on a fundamental algorithm of three dimensional computer graphics namely z bu ering An imple mentation of the z bu er method in a lazy functional language behaves in a quite di erent manner to the traditional imperative counterpart The main result of this paper is to show that the lazy z bu er is a scan line method The e ective di erence between scan line ...

And therefore, z λ < λ < λz and rz = λz/λ>1 and r z = z λ /λ <1. In this paper, we attempt to improve on the upper level set (ULS) scan system by improving the nodal quality and quantity of the upper level set tree, using PULSE, the progressive upper level set scan system. Here we generalize the ULS notion of the rank of a cell, while the original ULS algorithm ranked cells only by a single res...

And therefore, z λ < λ < λz and rz = λz/λ>1 and r z = z λ /λ <1. In this paper, we attempt to improve on the upper level set (ULS) scan system by improving the nodal quality and quantity of the upper level set tree, using PULSE, the progressive upper level set scan system. Here we generalize the ULS notion of the rank of a cell, while the original ULS algorithm ranked cells only by a single res...