2-COLOR NEAR-FIELD ECLIPSING Z-SCAN TECHNIQUE FOR THE DETERMINATION OF NONLINEAR REFRACTION

We propose a near-field eclipsing Z-scan technique for the measurement of nonlinear refraction of optical materials. The technique does not require sample displacement as in previous Z-scan and eclipsing Z-scan experiments but preserves the high sensitivity of the eclipsing Z-sca n method and the experimental simplicity of the Z-scan technique. As a n example of the feasibility of the new technique, the dye solution's thermal nonlinear refraction is measured with increased sensitivity in comparison with the Z-scan method. (C) 1997 Optical Society of Americ a [S0740-3224(97)01212-5].