An optical multilayer detection array for ultrasonic measurements is presented. The probe comprises a dielectric interference filter structure that is evaporated onto a glass plate. An incident acoustic pressure signal deforms the layer system, and the induced modulation of the optical reflectance is determined by a simple optical detection scheme. The principle of measurement is demonstrated by a line scan through the focus of a broadband transducer and can be applied to rapid two-dimensional characterization of ultrasonic fields. The high temporal and spatial resolution of the measurements is combined with high sensitivity and durability of the probe, and, in contrast with fiber-tip multilayer hydrophones, the multilayer detection array provides signals that are not influenced by acoustic resonances and diffraction phenomena.
© 1999 Optical Society of America
(110.2970) Imaging systems : Image detection systems
(110.7170) Imaging systems : Ultrasound
(120.4640) Instrumentation, measurement, and metrology : Optical instruments
(170.3880) Medical optics and biotechnology : Medical and biological imaging
(230.4170) Optical devices : Multilayers
V. Wilkens and Ch. Koch, "Optical multilayer detection array for fast ultrasonic field mapping," Opt. Lett. 24, 1026-1028 (1999)