The authors designed an improved wedge shaped cell for measuring
Lambert absorption coefficient spectra \alpha(\nu) of highly
absorbent liquids. The design allows for accurate determination
of the apex angle of the wedge, sealing the cell, and injection
of the liquid without disassembling the cell. They measured
\alpha(\nu) for water through the 500-12500cm-1
wavenumber region to determine the range of \alpha(\nu) for which
the cell provided accurate measurements. They then determined the
imaginary part of the complex refractive index
N(\nu)=n(\nu)+ik(\nu) from \alpha(\nu) and used Kramers-Kronig
methods to compute n(\nu) from k(\nu).
D. M. Wieliczka, S. Weng, M. R. Querry, "Wedge shaped cell for
highly absorbent liquids: infrared optical constants of water,"
Appl. Opt.,28, 1714-1719 (1989).