THIRD-ORDER NONLINEARITIES AND OPTICAL LIMITING OF C60 POLYURETHANE–UREA FILMS

Abstract

We report on the measurement of the nonlinear optical absorption and refraction coefficients of C60-containing polyurethane–urea films on a nanosecond scale at a 532-nm wavelength, using the Z-scan technique. The optical limiting properties were also observed. The results show that the C60 polyurethane–urea is a kind of homogeneous material with a range of C60 content. With the difference in C60 content in polymers, the optical limiting properties are many and the required transmittance and transmitted energy can be altered depending on the C60 content in polymers. We suggest that the third-order nonlinearities and optical limiting behavior are consistent with excited-state absorption (reverse saturable absorption) as a mechanism.