Effect of residual Doppler averaging on the probe absorption in cascade type system: A comparative study

Abstract

Effect of residual Doppler averaging on the probe absorption in an alkali vapor medium in the presence of a coherent pump beam is studied analytically for the Ξ type system. A coherent probe field is assumed to connect the ground level with the intermediate level whereas a coherent control beam is supposed to act between the intermediate energy level and the uppermost level. Optical Bloch equations (OBE) for a three-level Ξ type system and a four-level Ξ type system are derived by using density matrix formalism. These equations are solved by an analytic method to determine the probe response, which not only depends on the wavelength difference between the control (pump) field and the probe field but shows substantially different features depending on whether the wavelength of the control field is greater than that of the probe field or the reverse. The effect of temperature on probe response is also shown. Enhancement in probe absorption and additional features are noticed under a strong probe limit at room temperature. The four-level Ξ type system has two ground levels and this leads to substantial modification in the simulated probe absorption as compared to the three-level system.

The effect of the Doppler mismatch in microwave electrometry using Rydberg electromagnetically induced transparency and Autler–Townes splitting

“…where Δ f is AT-splitting interval when microwave and atom resonance. D is equal to 1 when the coupling laser frequency is scanned, while D = λ p λ c when the probe laser frequency is scanned, called residual Doppler effects [19][20][21][22]. There is no Doppler mismatch if the coupling laser frequency is scanned, however, more atoms are populated to the excited states by the probe laser which resonates with atomic transition.…”

“…Therefore, the scheme of scanning the frequency of the probe laser is preferred and adopted by most experiments and applications. The research on D is very important and has attracted the attention of many research groups [21,26,[27][28][29][30].…”

High resolution spectroscopy of Rb in magnetic field by far-detuning electromagnetically induced transparency

“…1(b) for different frequency detunings, where the Doppler effect has also be included. [21,22] The spectral line intensities are all normalized as the detunings will decrease the line intensities greatly. However, the high resolution of EIT spectroscopy is often obscured by the complex relaxation processes due to the strong optical coupling between states |2 and |3 , which evolves into another spectral terminology, DROP.…”