Effects of light on cesium 6S–8S two-photon transition

This work presents a simple approach for determining the contribution of Lorentzian or Gaussian statistics by data fitting the spectrum to a Voigt profile. The fitting result shows that the Lorentzian width remains almost constant (∼1.51 MHz) and the Gaussian width increases (∼1.0–2.0 MHz) while changing the laser intensity or atomic density. The frequency shift associated with the cesium 6S–8S two-photon transition as a function of laser power is approximately -7.25(45)Hz/(mW/mm2), agrees closely with the theoretical value. These results can be used to improve the optical secondary frequency standard in the near infrared region.