Formation of cesium dimers and observation of high-resolution dimer spectra in spatially restricted Cs vapor

In this communication, we demonstrate a new use of the micrometric (700 μm) thick, high-quality optical cell filled with Cs vapor that intrinsically contains extremely small concentration of Rb atoms. When heated to temperature about 200 °C such alkali mixture consists of Cs2 dimers and Cs atoms together with very small number of Rb atoms. We use the Rb atomic spectrum as a reference one, in order to measure spectral profiles and frequency positions of the observed spectral lines of Cs2 molecules within the B1Пu←X1Σg+ absorption band in the spectral region around the D2 resonance line of Rb with wavelength λ = 780.24 nm.