We propose a novel all-optical focused ultrasound detector for intravascular optoacoustic imaging and demonstrate its imaging capabilities experimentally; the detector has a bandwidth of more than 75MHz and a spatial resolution of at least 50μm.
One of the main challenges in intravascular photoacoustic (IVPA) imaging is the limited sensitivity and bandwidth of miniaturized piezoelectric probes. Optical detectors of ultrasound can drastically improve both these features, but often lack acoustic focusing. In this work, we developed a focused ultrasound detector by integrating a miniaturized acoustic lens, made out of glass, with a silicon-photonics-based detector. A detection bandwidth of up to 80 MHz and lateral resolution beyond 50 µm was demonstrated with a lens diameter of 0.8 mm. Our device is transparent in the near-infrared window, simplifying its integration in a miniaturized IVPA probe.
Silicon photonics represents an attractive platform for optical sensing of ultrasound owing to the high light confinement it can achieved, which can enable the development of detector with sub-micron sizes. However, the small elasto-optic coefficients of silicon and silica limit the sensitivity of conventional silicon-on-insulator (SOI) sensors, in which the silicon core is surrounded by a silica cladding. In this work, we demonstrate an order-of-magnitude increase in the response of a silicon-photonics waveguide to ultrasound by replacing the silica over-cladding with bisbenzocyclobutene (BCB) - a transparent polymer with a high elasto-optic coefficient.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.