CoupledEOT · Integrated optical coupling for low loss electro-optic interconnects

The development of electrooptic transducers, that can effectively interface between microwave and optical frequencies, is critical to upcoming quantum technologies, such as distributed quantum computing over multiple superconducting qubit processors and the inclusion of any microwave-based quantum technologies in a future quantum internet. These transducers would furthermore also benefit classical applications where sensitive all-optical detection of microwave and THz frequency signals is beneficial, such as in radars and remote sensing. However, the development of such devices has been challenging owing to the more than 5 orders of magnitude energy gap between the microwave and optical frequencies. Only a handful of quantum-signal-enabled transducers exist in a few research labs around the world with no commercial availability. In this project, we develop a critical new functionality for one of the most successful platforms, i.e. ultra-low loss electrooptic transducers based on high purity bulk optical crystals. In CoupledEOT, we will develop a new optical coupling method for high index whispering gallery mode resonators that is high efficiency, easy to operate and robust against thermal contractions. This will make the highest performance quantum transducers compatible with common packaging solutions and commercial applications both in the quantum and classical domains.