The optical constants of liquid mercury have been measured by ellipsometry at a wavelength of 5461 Å. The measured results are n = 1.485 and K = 3.061. Discrepancies among values from the literature are discussed and the magnitude of the important sources of error are evaluated. The effects on the measured index of several different types of surface films between the mercury and several contact media have been calculated and compared. Errors in alignment are shown to cause large changes in the measured refractive index as well as an apparent dependence upon the angle of incidence.
LESLIE E. SMITH and ROBERT R. STROMBERG, "Measurement of Optical Constants: Optical Constants of Liquid Mercury at 5461 Å," J. Opt. Soc. Am. 56, 1539-1542 (1966)