Laser-spectroscopic investigations of the lithium resonance lines

Optical pumping and electromagnetically induced transparency in a lithium vapour

“…Part of the pump laser beam was sent to an interferometer with path length difference of approximately 3.3 m. This enabled the spectrum to be put on a linear frequency scale and provided an absolute calibration of the frequency difference of the pump laser across a 2 GHz scan range to an accuracy of ≈60 MHz. More precise calibration of the frequency difference was achieved by fitting a quadratic function to the interference fringes and setting the spacing between two assigned features in the spectrum to values obtained from the literature [6,16,17].…”

“…Here, the lasers are resonant with transitions from a common ground state to different excited states. These peaks differ in frequency from the central peak by the hyperfine splitting of the two excited states which is 91.8 MHz [6,17]. For each of the peaks there are two possible subsystems involved due to Doppler shifting, one for each of the hyperfine ground states shown in figure 4.…”

Quantitative element analysis by isotope dilution in diode laser graphite furnace atomic absorption spectrometry

“…Considering the above-mentioned criteria, the only element of this group suitable for isotope dilution measurements in GFAAS is lithium (resonance line, data see [71,72]). The transition at 208.9 nm in the spectrum of boron can certainly be matched by SHG of laser diode radiation emitted at 418 nm, but the full Doppler width of the isotope lines as well as the isotope shift both amount to approximately 17 GHz and, thus, a Doppler-free technique should be applied.…”