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

Abstract

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 δɛ=−0.168 and the birefringence Δn(0)=0.166 indicate considerable anisotropy. The calculated SHG of the dominant component χ322(2)(ω) is about d32=5.3pm/V at λ=1064nm (1.165eV) which is in excellent agreement with the available experimental data (d32=5.49pm/V) obtained using pulsed Nd:YAG laser at wavelength λ=1064nm (10ns, 3 mj 10kHz). To analyze the origin of the high SHG of bismuth subcarbonate Bi2O2CO3 we have correlated the features of χ322(2)(ω) spectra with the features of ɛ2(ω) spectra as a function of ω/2 and ω.