Optoacoustic imaging using thin polymer etalon

Optical detection of ultrasound is a promising technique for high frequency imaging arrays. Detection resolution approaches the optical resolution, which can be on the order of the optical wavelength. We describe here an optical technique for ultrasound detection based on a thin (10 mu m) Fabry-Perot etalon optimized for high resolution imaging. The signal to noise ratio (SNR) approaches that of an ideal piezoelectric transducer over a 100 MHz bandwidth. Array functionality is demonstrated by scanning a probe beam along a line. Thermoelastic excitation was applied to generate acoustic waves in a test phantom containing a single "pointlike" source. An image of the source was reconstructed using signals acquired from the etalon detector array. (C) 2005 American Institute of Physics.