We determine the nonlinear refractive index, n2, in an optical material through the direct measurement of the phase of an ultrashort optical pulse, using the technique of frequency-resolved optical gating. This method results in the accurate measurement of n2, with the error dominated by the uncertainty in the fluence measurement. We measure n2 in fused silica and in potassium dihydrogen phosphate at 804 and 402 nm. These results are consistent with those from previous measurements of n2 in these materials, and the measured dispersion of n2 in fused silica agrees with theoretical predictions.
© 1996 Optical Society of America
Original Manuscript: June 7, 1996
Published: November 15, 1996
A. J. Taylor, Tracy Sharp Clement, and G. Rodriguez, "Determination of n2 by direct measurement of the optical phase," Opt. Lett. 21, 1812-1814 (1996)