Wavelengths of seven spectral lines of Fe I, Ge I, and Pt I between 1932 Å and 1938 Å have been measured with uncertainties of less than 1×10<sup>−4</sup> Å (5 parts in 10<sup>8</sup>) with Fourier-transform spectroscopy. These lines provide accurate standards for wavelength calibration of ArF excimer lasers operating at 193 nm. Previously reported wavelengths of Fe I, Cu II, and Ge I were evaluated for calibration of the absolute wavelength scale. Calibrations based on Fe I and Ge I were found to differ systematically by several parts in 10<sup>8</sup>. A calibration based on Cu II was internally inconsistent at a level of 2 parts in 10<sup>7</sup> and was not used. Improved wavelengths for an additional 147 lines of Pt I and Pt II and 161 lines of Kr II in the region 1636 Å to 3151 Å are also reported.
© 2004 Optical Society of America
Gillian Nave and Craig J. Sansonetti, "Reference wavelengths in the spectra of Fe, Ge, and Pt in the region near 1935 Å," J. Opt. Soc. Am. B 21, 442-453 (2004)