Mercep, E. ; Jeng, G.* ; Morscher, S. ; Li, P.C.* & Razansky, D. Hybrid optoacoustic tomography and pulse-echo ultrasonography using concave arrays. IEEE Trans. Ultrason. Ferroelectr. Freq. Control. 62, 1651-1661 (2015) Caballero, M.A.A. ; Rosenthal, A. ; Bühler, A. ; Razansky, D. & Ntziachristos, V. Optoacoustic determination of spatio-temporal responses of ultrasound sensors. IEEE Trans. Ultrason. Ferroelectr. Freq. Control. 60, IEEE, 1234-1244 (2013) Rosenthal, A. ; Ntziachristos, V. & Razansky, D. Optoacoustic methods for frequency calibration of ultrasonic sensors. IEEE Trans. Ultrason. Ferroelectr. Freq. Control. 58, 316-326 (2011)