Endoscopic ultrasound imaging systems require compact, low-power probes with a dense array of sensing elements. At the same time, the cabling inside the probe tube that interfaces with the external processing unit should be minimal. State-of-the-art ultrasound imagers that utilize CMUTs and PMUTs require integrating each transducer’s power-hungry analog frontend on probe, making it more difficult to satisfy the safe power limit. To address this, we propose the use of silicon microring resonators (MRRs) as ultrasound sensors. Their small element size (10-20 μm in diameter) allows us to realize arrays with 50μm sensor pitch; furthermore, due to the small diameter of optical fibers compared to micro-coaxial cables, we are able to remote frontend circuitry outside of the body and minimize probe tube size. With monolithic silicon photonics, we can co-integrate low-power thermal tuning circuitry with each sensor on the probe as well as eliminate packaging parasitics from heterogeneous integration. We envision a dual-chip scheme with a dense, low-power sensing chip inside of the body and a companion low-noise readout chip outside of the body.
Project is currently funded by: Federal