Observation of atomic-pair absorption with an incoherent source

Area of Science:

• Atomic, Molecular, and Optical Physics
• Condensed Matter Physics

Background:

• Atomic vapor studies are crucial for understanding interatomic interactions.
• Absorption spectroscopy provides a window into electronic transitions and molecular potentials.

Purpose of the Study:

• To experimentally observe and quantify atomic-pair absorption in barium (Ba) and barium-thallium (Ba-Tl) vapors.
• To characterize the spectral properties of this absorption, including peak wavelength and width.

Main Methods:

• Utilized a white-light source for broad spectral coverage.
• Employed atomic vapor cells with controlled densities (approximately 10^17 atoms/cm^3).
• Measured absorption spectra to identify and quantify pair absorption features.

Main Results:

• Successfully observed atomic-pair absorption in both Ba-Ba and Ba-Tl systems.
• Quantified absorption coefficients: 2.9% cm^-1 for Ba-Ba and 2.3% cm^-1 for Ba-Tl.
• Determined that absorption maxima occur at the predicted R = infinity wavelength with a FWHM of ~15 cm^-1.

Conclusions:

• The experimental results confirm the theoretical predictions for atomic-pair absorption.
• This study demonstrates a method for probing interatomic interactions via broadband absorption spectroscopy.
• The observed absorption characteristics provide valuable data for modeling atomic vapor properties.