Sensing sound with light

Ivan Maksymov Low Res Edit 01479 September 2016:

New research from CNBP  researcher Ivan Maksymov and CNBP CI Andrew Greentree outlines a new way to detect ultrasound in the body.

The researchers showed that a plasmonic nanoantenna – like a television antenna, but 1000 times smaller than the width of a human hair – can be used to sense ultrasound in the body.

“The biggest problem with sensing ultrasound is the size of the receiver” explains Dr Maksymov. “By using metal nanoparticles, we have shown that we can shrink the size of the hydrophone.” Smaller detectors mean that ultrasound can be probed in smaller areas of the body. “The key is to look inside the smallest blood vessels.”

Solving the work was challenging as the device operates in the so-called deep subwavelength regime – where the size of the device is much smaller than the wavelength of both the light and the sound.

The research appeared in the journal Scientific Reports on the 9th of September, 2016.

Journal: Scientific Reports.

Publication title: Plasmonic nanoantenna hydrophones.

Authors: Ivan S. Maksymov & Andrew D. Greentree.

Abstract: Ultrasound is a valuable biomedical imaging modality and diagnostic tool. Here we theoretically demonstrate that a single dipole plasmonic nanoantenna can be used as an optical hydrophone for MHz-range ultrasound. The nanoantenna is tuned to operate on a high-order plasmon mode, which provides an increased sensitivity to ultrasound in contrast to the usual approach of using the fundamental dipolar plasmon resonance. Plasmonic nanoantenna hydrophones may be useful for ultrasonic imaging of biological cells, cancer tissues or small blood vessels, as well as for Brillouin spectroscopy at the nanoscale.

The paper is available online.