UC Santa Cruz researchers achieve atomic spectroscopy on a chip

SANTA CRUZ, CA--Researchers at the University of California, Santa Cruz, have performed atomic spectroscopy with integrated optics on a chip for the first time, guiding a beam of light through a rubidium vapor cell integrated into a semiconductor chip.

Atomic spectroscopy is a widely used technique with diverse applications. Based on the interactions of light and matter, spectroscopy is often used to identify substances by the wavelengths of light they absorb or emit. Conventional systems have many large components, whereas the compact, fully planar device developed at UCSC enables the study of atoms and molecules on a chip-based platform with integrated optics, said Holger Schmidt, associate professor of electrical engineering.

Schmidt's group and his collaborators at Brigham Young University described the first monolithically integrated, planar rubidium cell on a chip in a paper published in the June issue of Nature Photonics. The first author of the paper is Wenge Yang, a postdoctoral researcher in Schmidt's lab at UCSC's Baskin School of Engineering.

According to Schmidt, potential applications for this technology include frequency stabilization for lasers, gas detection sensors, and quantum information processing.

"To stabilize lasers, people use precision spectroscopy with bulk rubidium vapor cells. We could build a little integrated frequency stabilization chip that would do that more easily than a conventional frequency stabilization circuit," Schmidt said.

That project is already under way in Schmidt's lab. Other applications, such as quantum information processing, are more long-term goals, he said.