Full-Field Imaging of GHz Film Bulk Acoustic Resonator Motion

Journal Article · Wed Oct 01 00:00:00 EDT 2003 · IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control

DOI:https://doi.org/10.1109/TUFFC.2003.1244744· OSTI ID:911972

Telschow, Kenneth Louis; Deason, Vance Albert; Cottle, David Lynn; Larson, III, J D

A full-field view laser ultrasonic imaging method has been developed that measures acoustic motion at a surface without scanning. Images are recorded at normal video frame rates by using dynamic holography with photorefractive interferometric detection. By extending the approach to ultra high frequencies, an acoustic microscope has been developed that is capable of operation at gigahertz frequency and micron length scales. Both acoustic amplitude and phase are recorded, allowing full calibration and determination of phases to within a single arbitrary constant. Results are presented of measurements at frequencies of 800-900 MHz, illustrating a multitude of normal mode behavior in electrically driven thin film acoustic resonators. Coupled with microwave electrical impedance measurements, this imaging mode provides an exceptionally fast method for evaluation of electric-to-acoustic coupling of these devices and their performance. Images of 256 /spl times/ 240 pixels are recorded at 18 fps rates synchronized to obtain both in-phase and quadrature detection of the acoustic motion. Simple averaging provides sensitivity to the subnanometer level at each pixel calibrated over the image using interferometry. Identification of specific acoustic modes and their relationship to electrical impedance characteristics show the advantages and overall high speed of the technique.

• Research Organization: Idaho National Lab. (INL), Idaho Falls, ID (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: DE-AC07-99ID-13727
• OSTI ID: 911972
• Report Number(s): INEEL/JOU-02-01625; TRN: US200801%%417
• Journal Information: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, Vol. 50, Issue 10
• Country of Publication: United States
• Language: English

Related Subjects

99 - GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
ACOUSTICS
AMPLITUDES
CALIBRATION
DETECTION
HOLOGRAPHY
IMPEDANCE
INTERFEROMETRY
LASERS
MICROSCOPES
QUADRATURES
RESONATORS
SENSITIVITY
THIN FILMS
ULTRASONIC WAVES
VELOCITY
acoustic resonator
film bulk
full-field imaging
laser ultrasonics
lateral modes