Determining hyperfine transitions with electromagnetically induced transparency and optical pumping

A system is designed to observe the phenomena of electromagnetically induced transparency and optical pumping in cesium D₁ and D ₂ lines at room temperature. When a pump laser is frequency-locked on the top of a hyperfine transition and the frequency of the probe laser scans over another hyperfine transition, a spectrum of V-type electromagnetically induced transparency or an optical pumping can be observed depending on whether the two lasers share a common ground state. Therefore, these results can be used to identify the unknown hyperfine transitions of the D₁ line transitions. For educational purposes, this system is helpful for understanding the electromagnetically induced transparency and the optical pumping.