UC Santa Cruz researchers achieve atomic spectroscopy on a chip

The key to the group's achievement is their development of hollow-core optical waveguides based on antiresonant reflecting optical waveguide (ARROW) principles. In previous publications, Schmidt and his collaborators have described other uses of ARROW waveguides integrated into chips using standard silicon fabrication technology (see earlier press release at http://press.ucsc.edu/text.asp?pid=578).

To perform atomic spectroscopy, the researchers incorporated rubidium reservoirs into a chip, connecting the reservoirs to hollow-core waveguides so that the optical beam path is filled with rubidium atoms. The resulting vapor cell is completely self-contained and has an active cell volume about 80 million times smaller than a conventional cell, Schmidt said.

"We used rubidium as a proof of principle, but this technique is applicable to any gaseous medium. So it has potentially far-reaching implications," Schmidt said.

In addition to its use in laser frequency stabilization, rubidium vapor is widely used in quantum optics experiments and has been used to slow the speed of light.

"Fundamental concepts in quantum information processing have been demonstrated in principle using bulk rubidium systems. To be practical you can't have big optical tables in all the places you would want to use it, but now we can make this technology more compact and portable," Schmidt said.

In addition to Schmidt, the coauthors of the Nature Photonics article include Donald Conkey and Aaron Hawkins of Brigham Young University, as well as UCSC graduate student Bin Wu and postdoctoral researcher Dongliang Yin. This research was supported by the National Science Foundation and the Slow Light Program of the Defense Advanced Research Projects Agency.