Oscillator strength

The dimensionless oscillator strength characterizes the strength of the coupling of a transition between two specific quantum states (e.g. an atom ) and electromagnetic radiation . ${\displaystyle f}$

The name comes from the semi-classical model of a harmonic of the atomic core bound electron , which by the electric field to vibrations is driven ( Lorentz Oscillator model).

The oscillator strength is linked to the quantum mechanical cross section by: ${\displaystyle \sigma (\lambda )}$

${\displaystyle f={\frac {4\cdot m_{\mathrm {e} }\cdot c^{2}\cdot \epsilon _{0}}{e^{2}}}\cdot \int {\frac {1}{\lambda ^{2}}}\,\sigma (\lambda )\,d\lambda }$

With

• ${\displaystyle m_{\mathrm {e} }}$: Electron mass
• ${\displaystyle c}$: Speed ​​of light
• ${\displaystyle \epsilon _{0}}$: electric field constant
• ${\displaystyle e}$: Elementary charge
• ${\displaystyle \lambda }$: Wavelength .

The Thomas-Reiche-Kuhn sum rule applies .