%0 Journal Article
%K Wavelength
%K Nonlinear optical properties (NLO)
%K Spectroscopic ellipsometry
%K Harmonic generation
%K Bismuth compounds
%K Antiferromagnetic materials
%K Refractive index
%K Nonlinear optical coefficients
%A A Kumar
%A R.C Rai
%A N.J Podraza
%A S Denev
%A M Ramirez
%A Y.-H Chu
%A L.W Martin
%A J Ihlefeld
%A T Heeg
%A J Schubert
%A D.G Schlom
%A J Orenstein
%A Ramamoorthy Ramesh
%A R.W Collins
%A J.L Musfeldt
%A V Gopalan
%B Applied Physics Letters
%D 2008
%G eng
%R 10.1063/1.2901168
%T Linear and nonlinear optical properties of BiFeO3
%V 92
%X Using spectroscopic ellipsometry, the room temperature refractive index and absorption versus wavelength of the ferroelectric antiferromagnet bismuth ferrite, BiFe O3, are reported. The material has a direct band gap at 442 nm wavelength (2.81 eV). Using optical second harmonic generation, the nonlinear optical coefficients were determined to be d15 d22 =0.20±0.01, d31 d22 =0.35±0.02, d33 d22 =-11.4±0.20, and ∫ d22 ∫ =298.4±6.1 pmV at a fundamental wavelength of 800 nm. © 2008 American Institute of Physics.