Measurement of the populations of metastable levels in gadolinium vapor by diode laser-based UV and near-IR absorption spectroscopy

• Published in: Optics communications 2002-11, Vol.212 (4), p.293-300
• Main Authors: Jung, E.C, Ko, Kwang-Hoon, Rho, S.P, Lim, C, Kim, Cheol-Jung
• Format: Article
• Language: English
• Subjects: Absorption spectroscopy; Atomic and molecular physics; Atomic properties and interactions with photons; Atomic spectra; Biological and medical applications; Diode laser; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Gadolinium; Laser spectroscopy; Optics; Physics; Ultraviolet; Visible and ultraviolet spectra
• ISSN: 0030-4018; 1873-0310
• DOI: 10.1016/S0030-4018(02)01961-2

The metastable populations of gadolinium atoms, which were generated by an electron beam gun, were measured by diode laser-based absorption spectroscopy. Transitions originating out of the ground and low-lying metastable levels were investigated in the spectral range of 390–394 nm. A tapered semiconductor power-amplifier which was seeded by a single-mode external-cavity diode laser was used as a fundamental light source for the second-harmonic generation in the ultraviolet wavelength range. The population appears to be frozen at an atomic excitation temperature of ∼600 K, which is about 1/4 of the heated surface temperature. The results obtained from the ultraviolet absorption spectra are compared to those obtained from the near-IR absorption spectra with wavelength ranges of 673–692 and 773–775 nm.