pISSN 0374-4914 eISSN 2289-0041

## Article

New Phys.: Sae Mulli 2020; 70: 625-629

Published online July 31, 2020 https://doi.org/10.3938/NPSM.70.625

## Dependences Comparison of the Polarization Spectroscopy Signal on Pump Beam Intensity and Temperature for closed transition lines of $^{85}\text{Rb}$ and $^{87}\text{Rb}$

Jeongyoun JEONG, Sanglok LEE, Geol MOON*

Department of Physics, Chonnam National University, Gwangju 61186, Korea

Correspondence to:cnuapi@jnu.ac.kr

Received: April 21, 2020; Revised: June 15, 2020; Accepted: June 15, 2020

### Abstract

We investigate the dependence of the polarization spectroscopy signal on the pump beam intensity and the vapor cell temperature around the $F_g=3\rightarrow F_e=4$ closed transition line of $^{85}$Rb and the $F_g=2\rightarrow F_e=3$ closed transition line of $^{87}$Rb, and we analyze the amplitudes of those signals. We observe that the temperature dependences of the polarization spectroscopy signal around the closed transition lines of $^{85}$Rb and $^{87}$Rb shows different tendencies, and that the temperature dependence of the polarization spectroscopy signal on the pump beam intensity. Interestingly the different temperature dependence of two isotopes comes from the difference in energy spacing between its hyperfine structure energy levels. It was theoretically confirmed that the signal amplitude of the closed transition line is affected by overlapping with the cross-over signal due to the increase in line width of the cross-over spectral signal depending on the temperature dependence.

Keywords: Polarization spectroscopy, Rubidium atom,vapor cell temperature, Pump beam intensity