We introduce a new experimental apparatus for cold atom based on an atom chip setup. It is going to
feature for the first time the ability to interchange the atom chip frequently and rapidly. The setup will be paired with
photonic structures on-chip for the detailed study of matter-light interactions. Here, we present the design of the new
apparatus and present first ideas on how to use the unique combination of cold-atom technology with interchangeable
photonics components, both, for basic research and applications to modern information technologies.
Tight confinement of light in photonic cavities helps realize high optical intensity with strong field gradients. We designed a nanoscale resonator device based on a one-dimensional photonic crystal slot cavity. Our design allows for highly localized optical modes with theoretically predicted quality factors (Q factors) in excess of 10 6 . The design was implemented experimentally both in a high-contrast refractive index system (silicon), as well as in medium refractive-index-contrast devices made from aluminum nitride. We achieved an extinction ratio of 21 dB in critically coupled resonators using an on-chip readout platform with loaded Q as high as 33,000. Our approach holds promise for ultrasmall optomechanical resonators for high-frequency operation and sensing applications.
We present a numerical framework for the simulation of lasers in the time domain. The algorithm is based on the finite-difference time-domain method, which has been extended to include material gain by using auxiliary differential equations for a frequency dependent conductivity. The algorithm is applied to the simulation of micro-disk lasers based on an erbium doped SiO<sub>2</sub> material system in order to obtain a CMOS compatible fabrication process. Lasing behavior and lasing threshold is studied in two and three dimensions for single and multi-disk systems.