A cavity quantum electrodynamics system consisting of quantum dots in a micropillar cavity may form an essential building block for the creation of a quantum network. Current systems do not allow...Show moreA cavity quantum electrodynamics system consisting of quantum dots in a micropillar cavity may form an essential building block for the creation of a quantum network. Current systems do not allow for the scaling, in a simple manner, to a large network. Therefore, we introduce a scalable approach by coupling a micropillar cavity to single-mode fibers. The steps taken to achieve the fiber coupling are explained and the first tests for researching a fiber coupled cavity quantum electrodynamics system are shown. The first tests show that full input-output fiber based polarization control of a micropillar cavity at 3.5 K is possible which is important for a photon polarization based quantum network. Several experimental challenges are shown and discussed. Despite the experimental challenges, the first tests may pave the way for a more scalable approach for building a large-scale quantum network.Show less
We measured the homogeneous linewidth $\Gamma_h$ of ytterbium atoms inside a whispering gallery mode ring resonator. Using two-pulse photon echoes, we looked at the temperature dependence of $...Show moreWe measured the homogeneous linewidth $\Gamma_h$ of ytterbium atoms inside a whispering gallery mode ring resonator. Using two-pulse photon echoes, we looked at the temperature dependence of $\Gamma_h$ for an applied external magnetic field of $B=0$ and $B=0.3$ T. We found a clear narrowing of the linewidth at each temperature. Furthermore, we found saturation of $\Gamma_h$ for $T<30$ mK for both $B=0$ and $B=0.3$ T. At $T=10$ mK and $B=0.3$ T, we have observed a linewidth of 22 kHz, which is very near the lifetime limit of 1 kHz. Our results for the homogeneous linewidth of ions in glasses show that current theories have to be reconsidered. In addition, our results for $T_2$ ensure that rare earth element-doped cavities are a candidate for AFC quantum memory.Show less
