Two- and three-photon absorption in chemical vapor deposition diamond

We report on the nonlinear optical properties (absorption and refraction) of monocrystalline chemical vapor deposition diamond studied by photoluminescence and Z-scan measurements. The studied spectral interval 2.8-6.2 eV can be divided into three regions in which the one-, two-and three-photon absorption (1PA, 2PA, 3PA) dominate. We obtained the values of 2PA and 3PA coefficients of diamond (alpha(2) = 0.9 cm/GW at 4 eV and alpha 3 = 2.3x10(-4) cm(3)/GW(2) at 3.1 eV) and of the nonlinear refractive index (8x10(-7) cm(2)/GW at 2.9 eV) for several irradiation photon energies. We interpret the measured spectral dependence of nonlinear absorption coefficients in terms of direct and indirect multiphoton absorption. (C) 2012 Optical Society of America