Sandia Labs and Arizona State U collaborate on quantum photonics

Sandia National Laboratories and Arizona State University are collaborating, as they say, "to push the boundaries of quantum technology and transform large-scale optical systems into compact integrated microsystems".

Nils Otterstrom, a Sandia physicist specializing in integrated photonics, is working on scaling down optical systems to the size of a chip. This innovation promises performance advantages and scalability for an array of applications from advanced computing to secure communications.

"Integrated photonics takes optical systems that are macroscale and makes them microscale," said Otterstrom, who earned his doctorate in applied physics from Yale and joined Sandia as a Harry S. Truman fellowship recipient.

"What we do in integrated photonics is develop novel devices and explore device physics to provide all the functionalities that we need to do fundamental research and create next-generation quantum microsystems."

Quantum collaboration

Otterstrom has been collaborating with Senior Director of Quantum Networking at Arizona State University Joe Lukens, who is an expert on using the frequency of light to carry quantum information for quantum computing and networking.

Quantum collaboration

Otterstrom has been collaborating with Senior Director of Quantum Networking at Arizona State University Joe Lukens, who is an expert on using the frequency of light to carry quantum information for quantum computing and networking.

Quantum photonics components

"In this frequency encoding paradigm, we need to create special types of beam splitters that instead take one color of light and split it into two," Otterstrom said. "What we have developed here at Sandia, in collaboration with professor Peter Rakich's team at Yale University, are these very efficient novel phase modulator devices."

The devices are based on suspended silicon waveguides that convey light and gigahertz soundwaves, which are generated by co-integrated aluminum nitride electro-mechanical transducers.

"The result is highly flexible optomechanical structures that acousto-optically split a photon into multiple frequencies. This allows you to do quantum information processing on a much higher dimensional space," Otterstrom said. "You can think about it as the light's color can actually carry the quantum information."

Next steps

Lukens' goal is to move work from proof-of-principle experiments to deployment in quantum networks. "In order to do that, we need systems with lower loss than what we can achieve today with commercial devices, and we need systems that are a bit cheaper," he said.

The collaboration is paying off. Sandia's Laboratory Directed Research program has awarded $17 million to advance the team's work in frequency-based quantum photonics. The funding comes in the form of a Grand Challenge program called Error-Corrected Photonic Integrated Qubits, or EPIQ.

Otterstrom said the funding will enable large-scale implementation and integration of the device physics explored in the early collaboration with Arizona State University to create a useful photonic qubit that can be error-corrected.