We investigate the feasibility of using optical fibre Bragg gratings for the sensing of ultrasonic fields for medical applications. In preliminary experimental investigations, ultrasonic waves with a frequency of 950kHz have been detected with a noise limited pressure resolution of approximately 10.2 atmospheres in a 3kHz measurement bandwidth.

We investigate the feasibility of using in-fibre Bragg gratings to measure ultrasonic fields for medical applications. Two signal processing schemes for interrogating the gratings are described. Preliminary results for each scheme (one a homodyne approach, the other a heterodyne one) give noise-limited pressure resolutions of and atm respectively, each within a 1 Hz bandwidth. The second scheme, however, gives a more stable response.

Absrruct -We investigate the feasibilty of using infibre Bragg gratings to measure ultrasonic fields for medical applications. Two signal processing schemes for interrogating the gratings are described. Preliminary results for each scheme (one a homodyne approach, the other a heterodyne) give a noise limited pressure resolution of 2.2 x 10-4