Fiber Bragg grating technology for biomedical ultrasound applications

Abstract

Fiber Bragg gratings (FBGs) are a class of optical sensors that have been used widely in non destructive testing and monitoring. These sensors are compact, robust, inexpensive and immune to electromagnetic interference. FBGs serve as wavelength selective mirrors that reflect light at the Bragg wavelength. An applied strain results in a shift in the Bragg wavelength, which can be used to detect physical parameters such as temperature and pressure. Recent work suggests that FBGs could have potential for measurements in the biomedical ultrasound frequency range. In this presentation, I will provide an overview of ongoing work in our group on employing FBGs for applications in therapeutic ultrasound. Specifically, I will discuss calibration of these sensors along with their use in passive cavitation detection. I will also present recent results on detecting nonlinear waveforms relevant to focused ultrasound along with temperature measurement for thermal therapy. We envisage that these sensors will be useful in laboratory research environments, and for specialized therapy applications in the clinical setting.