Purpose: The experimental investigation of an optical fiber Bragg grating (FBG) sensor for biomedical application is described. The FBG sensor can be used to measure sound pressure and temperature rise simultaneously in biological tissues exposed to ultrasound. The theoretical maximum values that can be measured with the FBG sensor are 73.0 MPa and 30 °C.
Methods: In this study, measurement of sound pressure up to 5 MPa was performed at an ultrasound frequency of 2 MHz. A maximum temperature change of 6 °C was measured in a tissue-mimicking material.
Results: Values yielded by the FBG sensor agreed with those measured using a thermocouple and a hydrophone.
Conclusion: Since this sensor is used to monitor the sound pressure and temperature simultaneously, it can also be used for industrial applications, such as ultrasonic cleaning of semiconductors under controlled temperatures.
Keywords: FBG; Viscous heating.