Integrated Reconfigurable Circulator

Background

Photonic Integrated Circuits (PICs) are optical systems that are integrated on a substrate, where the optical system includes a plurality of photonic functions, such as light generation, transmission, filtering, modulation, switching, and detection. PICs are analogous to electronic integrated circuits; however, they operate primarily in the optical domain. A typical PIC includes one or more photonic devices, which are combined with integrated-optics devices. Some highly desirable photonic devices have proven difficult to include in a PIC, including non-reciprocal devices, such as optical isolators, optical circulators, and Faraday rotators. Current non-reciprocal devices are relatively large, have fixed functionality, and require complex fabrication to integrate permanent magnetic material. Among the available circulators, none can be reversed. There is a demonstrable need for a simple, low loss, easily fabricated, reconfigurable non-reciprocal device suitable for integration in a PIC.

Description

Researchers at UC Santa Barbara have created a novel PIC device enabling reversible, low-loss, reconfigurable non-reciprocal optical signal routing within integrated optics platforms. The Integrated Reconfigurable Circulator is a monolithic PIC that allows dynamic reversal and reconfiguration of light signal paths across multiple ports. Leveraging a unique combination of a phase-sensitive microring waveguide, a magneto-optic layer, and an integrated electromagnet, this technology controls non-reciprocal phase shifts via electromagnetic fields. Reversing the current direction in the electromagnet switches the circulation direction of the optical signals, enabling rapid sub-nanosecond reconfiguration of port connectivity. This architecture overcomes the limitations of conventional non-reciprocal devices by eliminating fixed functionality, complex fabrication involving permanent magnetic materials, and large device footprints. It supports integration with other photonic components such as lasers and modulators, offering a cost-effective and compact solution for advanced photonic systems.

Advantages

• Fully reversible and reconfigurable optical circulation
• Low optical loss enabling efficient signal transmission
• Monolithic integration compatible with existing PIC platforms
• Eliminates need for permanent magnetic materials in fabrication
• Rapid sub-nanosecond switching of optical port connectivity
• Reduced manufacturing cost and complexity

Applications

Patent Status