Reflectance of lithium triborate crystal in the 6–12-eV region is measured with synchrotron radiation, and the principal values of optical constants are derived. Six absorption peaks are found in both X- and Y-polarized spectra. Among them the five transitions of the Y-polarized peaks and three of the X-polarized peaks are identified. The measurement suggests that the energy of the lowest conducting band 4A<sub>2</sub> is 7.3 eV rather than 7.57 eV, as previously reported.
© 1998 Optical Society of America
(190.4400) Nonlinear optics : Nonlinear optics, materials
(260.7210) Physical optics : Ultraviolet, vacuum
(300.6170) Spectroscopy : Spectra
(300.6560) Spectroscopy : Spectroscopy, x-ray
(340.6720) X-ray optics : Synchrotron radiation
Tian-Jie Chen, R. Tao, J. C. Rife, and W. R. Hunter, "Optical constants and related electronic energy bands of lithium triborate crystal in the 6 12-eV region," J. Opt. Soc. Am. B 15, 47-52 (1998)