Ultrasensitive plano-concave optical microresonators for ultrasound sensing. Issue 11 (November 2017)

• Record Type: Journal Article
• Authors: Guggenheim, James; Li, Jing; Allen, Thomas; Colchester, Richard; Noimark, Sacha; Ogunlade, Olumide; Parkin, Ivan; Papakonstantinou, Ioannis; Desjardins, Adrien; Zhang, Edward; Beard, Paul
• Is Part Of: Nature photonics. Volume 11:Issue 11(2017)
• Page Start: 714
• Page End: 719
• Publication Date: 2017-11
• Subjects: Photonics -- Periodicals; 621.36
• DOI: 10.1038/s41566-017-0027-x
• Languages: English
• ISSNs: 1749-4885

Abstract

Abstract Highly sensitive broadband ultrasound detectors are needed to expand the capabilities of biomedical ultrasound, photoacoustic imaging and industrial ultrasonic non-destructive testing techniques. Here, a generic optical ultrasound sensing concept based on a novel plano-concave polymer microresonator is described. This achieves strong optical confinement (Q -factors > 105 ) resulting in very high sensitivity with excellent broadband acoustic frequency response and wide directivity. The concept is highly scalable in terms of bandwidth and sensitivity. To illustrate this, a family of microresonator sensors with broadband acoustic responses up to 40 MHz and noise-equivalent pressures as low as 1.6 mPa per √Hz have been fabricated and comprehensively characterized in terms of their acoustic performance. In addition, their practical application to high-resolution photoacoustic and ultrasound imaging is demonstrated. The favourable acoustic performance and design flexibility of the technology offers new opportunities to advance biomedical and industrial ultrasound-based techniques. An optical-based scheme for ultrasound sensing provides very high sensitivity with excellent broadband acoustic frequency response and wide directivity.