Dispersion of the linear and nonlinear optical susceptibilities of Bismuth subcarbonate Bi2O2CO3: DFT calculations

The dispersion of the linear and nonlinear optical susceptibilities of bismuth subcarbonate Bi2O2CO3 are calculated using density functional theory (DFT). We have employed the state-of-art all-electron full potential linearized augmented plane wave (FP-LAPW) method. Calculations are performed within the recently modified Becke Johnson potential (mBJ) to obtain the self consistency conditions. The calculated linear optical susceptibilities exhibit a considerable anisotropy which is useful for second harmonic generation (SHG) and optical parametric oscillation (OPO). The calculated absorption coefficient show good agreement with the available experimental data. The values of calculated uniaxial anisotropy delta epsilon = -0.168 and the birefringence Delta n(0) = 0.166 indicate considerable anisotropy. The calculated SHG of the dominant component vertical bar chi((2))(322)(omega)vertical bar is about d(32) = 5.3 pm/V at lambda = 1064 nm (1.165 eV) which is in excellent agreement with the available experimental data (d(32) = 5.49 pm/V) obtained using pulsed Nd:YAG laser at wavelength lambda = 1064 nm (10 ns, 3 mj 10 kHz). To analyze the origin of the high SHG of bismuth subcarbonate Bi2O2CO3 we have correlated the features of vertical bar chi((2))(322)(omega)vertical bar spectra with the features of epsilon(2)(omega) spectra as a function of omega/2 and omega