Modeling the sensitivity dependence of silicon-photonics-based ultrasound detectors

source: © 2017 Optical Society of America

With recent advances in optical technology, interferometric sensing has grown into a highly versatile approach for ultrasound detection, with many interferometric detectors relying on optical waveguides to achieve high levels of sensitivity and miniaturization. In this Letter, we establish a practical model for assessing the sensitivity of silicon-photonics waveguides to acoustic waves. The analysis is performed for different polarizations, waveguide dimensions, and acoustic wave types. Our model was validated experimentally in the acoustic frequency band of 1–13 MHz by measuring the sensitivities of the two polarization modes in a silicon strip waveguide. Both the experimental results and theoretical prediction show that the transverse-magnetic polarization achieves a higher sensitivity and suppression of surface acoustic waves compared to the transverse-electric polarization for the geometries studied. [Read More…]

Fig. 2. Numerical calculation of normalized sensitivity ?? as a function of the waveguide width (??) and height (??) and polarization for (a), (b) the longitudinal acoustic wave in normal incidence and (c), (d) SAWs created in oblique incidence.

Shai Tsesses, Daniel Aronovich, Assaf Grinberg, Evgeny Hahamovich, and Amir Rosenthal “Modeling the sensitivity dependence of silicon-photonics-based ultrasound detectors”, Optics Letters Vol. 42, Issue 24pp. 5262-5265 (2017)