ABSTRACT
We report on the development of a diagnostic to measure the time-resolved column density and Doppler temperature of atomic vapors produced by laser ablation. The diagnostic is based on the strong frequency dependence of the atomic susceptibility near an electronic transition in the interrogated atomic species. Interference on the face of a fast photodetector between the several frequency components present in a sinusoidally phase-modulated probe beam will produce a time signature uniquely determined by the column density of atoms in the probed atomic state and the Doppler temperature of the atomic vapor. With the extensive, high precision atomic spectroscopy data available in the literature, it is possible to model the vapor and extract the desired parameters through comparison of the model result with the experimental data.
ABSTRACT
We describe an ultraviolet (uv) diode laser system for cooling trapped Yb(+) ions. Using four stages of thermoelectric cooling, 10 mW of light at 369.5 nm is obtained by cooling a 373.4-nm uv diode to approximately -20 degrees C. Frequency stabilization is provided by a diffraction grating mounted in the Littrow configuration which allows for a mode-hop free tuning range of approximately 25 GHz. In order to avoid water condensation, the diode laser and associated optics are placed inside an evacuated chamber. Saturated absorption spectroscopy utilizing an Yb hollow cathode lamp is performed. This laser system is currently being used to cool single ions in an experiment whose ultimate goal is to look for modern variation of the fine-structure constant.