| Electromagnetically induced transparency (EIT) is an important quantum interference effect. The main phenomenon is that medium for probe field absorption decrease significantly and the dispersion significantly enhanced via a strong coupling filed. Since it was discovered, it caused extensive concern. It has important application in laser without inversion, enhanced optical nonlinearly, slow light, four wave mixing, etc. In this paper, firstly we observe the free space electromagnetically induced transparency of rubidium atoms with a magnetic field. Then we mainly study the intracavity electromagnetically induced transparency with a magnetic field at room temperature.We can get a static magnetic field (<5G) which is parallel to the laser propagation direction by a solenoidal coil. At the beginning the EIT width will narrow down with the increase of magnetic field intensity. Then the EIT window split into several subwindows and the center EIT width broaden when the magnetic field continues to increase.As we all know, when a magnetic field is used, the Zeeman shift of the energy levels results in the formation of several subsystems. The net effect is to create multiple EIT windows. When the magnetic field is small (<3G), the distance between the subsystems is very close. This lead to the center EIT linewidth is significantly narrower than the original resonance. As the magnetic field continues to increase (>3G), the influence of the multiple EIT dips on the EIT width would not be significant. Then we study the intracavity electromagnetically induced transparency with a magnetic field. The experimental result shows that without the magnetic field the EIT medium can narrow the cavity linewidth to5MHz and the magnetic field can further reduce the cavity linewidth. The narrowest cavity linewidth can be2MHz which is half of the cavity linewidth without magnetic field. Based on experimental analysis we find that EIT linewidth is dominated in this process. |
PDF Full Text Request