Integrated photonics interferometric interrogator for a ring-resonator ultrasound sensor.

We present a compact integrated photonics interrogator for a ring-resonator (RR) ultrasound sensor, the so-called MediGator. The MediGator consists of a special light source and an InP Mach-Zehnder interferometer (MZI) with a 3 ×3 multi-mode interferometer. Miniaturization of the MZI to chip size enables high temperature stability and negligible signal drift.

On-chip silicon Mach-Zehnder interferometer sensor for ultrasound detection.

A highly sensitive ultrasound sensor based on an integrated photonics Mach-Zehnder interferometer (MZI) fabricated in silicon-on-insulator technology is reported. The sensing spiral is located on a membrane of size 121  μm×121  μm. Ultrasound waves excite the membrane's vibrational mode, which translates to modulation of the MZI transmission.