CAREER: AlGaAs-on-Insulator Integrated Quantum Photonics

Quantum computing promises to transform society in all aspects, from the rapid discovery of new drugs and vaccines to improving supply chain efficiency, real-time optimization of transportation and navigation, and the secure storage and transmission of personal information. While there are several contenders for the physical implementation of quantum computers, integrated photonics is advantageous for several reasons, including room temperature operation, device scalability, and long-distance connectivity using light.

Despite the remarkable advances in integrated quantum photonics within the last decade, existing photonic materials and devices have drawbacks and disadvantages that inhibit further improvement in scaling and efficiency. This proposal addresses these challenges through the development of a new quantum photonic platform based on AlGaAs-on-insulator, which has desirable properties for chip-scale quantum information processing with light, including ultra-low loss components that can be directly integrated with ultra-bright quantum light sources.

Through integration-driven discovery, research and development of AlGaAs-on-insulator quantum photonic devices will advance our understanding of the fundamental limits within which we can encode, process, store, and transmit quantum information. Interwoven with our research goals is a full-spectrum approach to developing new pathways for a diverse and vibrant quantum-ready workforce that spans K-8 learners and their families to high school, undergraduate, and graduate students.

The PI and his team will establish several new outreach activities and training programs, including: a remotely accessible quantum teaching lab, which will be offered to students enrolled at UCSB and Santa Barbara City College (SBCC); a summer research internship for the cohort of students at SBCC; a short-course Saturday series to bring regional high-school students from under-represented communities on campus for an interactive quantum learning experience with media arts and technology; and a new outreach program for K-8 students and their families to learn about quantum science and engineering.

Technical Description: This proposal addresses the development of AlGaAs-on-insulator integrated quantum photonic devices, which has not yet been explored for quantum information science and applications, yet it has desirable properties for chip-scale quantum computing including ultra-low waveguide loss, large second- and third-order optical nonlinearities, high index contrast and tight modal confinement, negligible two-photon absorption, ultra-bright entangled-pair sources, and direct integration of active components. To establish AlGaAs-on-insulator into an ultra-efficient, high-speed quantum photonic platform for measurement-based quantum computing and quantum communications, the PI and his team will develop the essential components for programmable quantum photonic circuits, including low-loss and high-performance entangled- and squeezed-light sources, optical filters, interferometers, modulators, pulse shapers, chip-to-fiber couplers, and integrated single-photon detectors.

This plan capitalizes on the PI’s expertise in integrated photonics and quantum optics, advanced quantum photonic testing capabilities in his lab, and the state-of-the-art clean room and nanofabrication facilities at UCSB. The PI and his team will develop fault-tolerant schemes and architectures for discrete- and continuous-variable quantum information processing, which may enable orders-of-magnitude improvement in processing speed and power efficiency compared to existing approaches.

AlGaAs-on-insulator quantum devices will address glaring technology gaps with existing photonic platforms, filling a long-sought need for scalable, reconfigurable, and energy-efficient quantum technologies in areas of critical need. The most intriguing features of this platform—room-temperature operation, all-on-chip integration pathways, intrinsic stability and scalability, and the large optical nonlinearities and low loss at telecommunication wavelengths—will also lead to innovative technologies for high-speed interconnects, quantum photonic transceivers, and repeaters that are required to meet the increasing global demands for high-bandwidth fiber and satellite communication networks.

Such technological advances will expand our nation’s global competitiveness in the rapidly evolving and growing quantum and classical information landscape.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.