Paper
1 March 1991 Recording and analysis of (high-frequency) sinusoidal vibrations using computerized TV-holography
Svein Ellingsrud, Ole Johan Lokberg, Hans Magne Pedersen
Author Affiliations +
Abstract
The RETRA 1000 TV-holography system has been further developed for analysis of high frequency vibrations, using automatic data acquisition. Special phase shift algorithms are executed by means of a PC-based image processing system. The phase shifts are effected by a built in electro-optic modulator, controlled by a two channel high-resolution digital frequency synthesizer. The optical (speckle) and electronic noise is reduced, using an automatic speckle averaging technique. Amplitude and phase distributions can be calculated and presented for frequencies up to 10 MHz. The lower limit for amplitude detection is below 1 nm (for HeNe laser), while the relative phase distribution is given with less than 3° accuracy under stable conditions. We show results where the technique has been used to analyze various vibrating test objects like a ceramic "crystal", a high frequency loudspeaker and finally an underwater acoustic transducer. The crystal had resonant modes from 3,8 to 7,8 MHz
© (1991) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Svein Ellingsrud, Ole Johan Lokberg, and Hans Magne Pedersen "Recording and analysis of (high-frequency) sinusoidal vibrations using computerized TV-holography", Proc. SPIE 1399, Optical Systems in Adverse Environments, (1 March 1991); https://doi.org/10.1117/12.26092
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CITATIONS
Cited by 2 scholarly publications.
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KEYWORDS
Crystals

Speckle

Acoustics

Transducers

Ceramics

Fringe analysis

Phase shifts

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