High-resolution Doppler-free spectra of Sm were measured in the 635–690-nm wavelength region by means of Doppler-free spectroscopy with a single-mode diode laser and a long vapor cell. Isotope shifts were determined to an accuracy of better than 8 MHz for 20 transitions originating mostly from the 4f<sup>6</sup>6s<sup>2</sup> <sup>7</sup>F<sub>J</sub> (J=0 to J=6) to 4f<sup>6</sup>6s6p <sup>9</sup>D°, <sup>9</sup>F°, and <sup>7</sup>G° levels. Specific mass shifts, field shifts, and changes in the mean-square nuclear charge radii were evaluated by King-plot analysis.
© 1999 Optical Society of America
Hyunmin Park, Miran Lee, E. C. Jung, Jonghoon Yi, Yongjoo Rhee, and Jongmin Lee, "Isotope shifts of Sm I measured by diode-laser-based Doppler-free spectroscopy," J. Opt. Soc. Am. B 16, 1169-1174 (1999)