Quantentechnologie

We present saturation and polarization laser spectroscopy experiments of indium vapor with a single color on the 410 nm transition and with two colors at 410 and 451 nm. The spectra observed by polarization spectroscopy are discussed in terms of a quantitative model. The line shapes observed with two-color spectroscopy can phenomenologically be described taking into account hyperfine changing collisions, velocity changing collisions, and dark resonances. As an application, we actively stabilized a 410 nm diode laser on the resonances of saturation and polarization spectroscopy, and obtained long term frequency stabilities in the 100 kHz–1 MHz range.