In optical detection of ultrasound, resonators with high Q-factors are frequently used to maximize sensitivity. However, in order to perform parallel interrogation, conventional interferometric techniques require an overlap between the resonator spectra, which is difficult to achieve with high Q-factor resonators. In this work, a new method is developed for simultaneous interrogation of optical resonators with non-overlapping spectra. The method is based on a phase modulation scheme for pulse interferometry (PM-PI) and requires only a single photodetector and sampling channel per ultrasound detector. Using PM-PI, parallel ultrasound detection is demonstrated with four high Q-factor resonators.

Date Published: 19 July 2019
PDF: 3 pages
Proc. SPIE 11077, Opto-Acoustic Methods and Applications in Biophotonics IV, 110770I (19 July 2019); doi: 10.1117/12.2526256

Published in SPIE Proceedings Vol. 11077:
Opto-Acoustic Methods and Applications in Biophotonics IV
Vasilis Ntziachristos; Roger Zemp, Editor(s)