Capturing light

L. Serradesanferm Córdoba

Nina Meinzer

David John Rogers

Sérgio Ricardo Muniz, K. M. F. Magalhães, Ph. W. Courteille +3 more

We use a dark-spot Zeeman-tuned slowing technique to measure the capture velocity in a sodium magneto-optical trap as a function of the trapping laser intensity. We expand on previous work by measuring the capture velocity over a broad range of light intensities. We observe that the capture velocity reaches a maximum value and then decreases with increasing light intensities, which might imply a minimum in the trap-loss rate. This observation supports a recently published explanation of the dependence of the trap-loss rates, at low intensities, based mainly on the escape velocity.

Bernhard W. Adams

Clayton R. Otey, Michelle L. Povinelli, Shanhui Fan

We describe a dynamically tuned system capable of capturing light pulses incident from a waveguide in a pair of microcavities. We use coupled mode theory to design a method for determining how to tune the microcavity resonant frequencies. The results show that pulses can be captured almost completely, with arbitrarily small reflected power. We optimize the pulse capture bandwidth by varying the cavity coupling constants and show that the maximum bandwidth is comparable to the resonant-frequency tuning range. Our system may be implemented using refractive-index tuning in a 2-D silicon photonic crystal slab. Current technology would allow for capture of pulses with widths as low as ~100 ps, with a holding time limited only by cavity loss rates.