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In this paper, we describe an improved system that visualizes the 3-D vibration modes on the device surface in quasi-real time without precision optical adjustment. We used three visible semiconductor lasers with adequately separated wavelengths. The incident angles of the lasers are set to detect the two in-plane vibrations and one out-of-plane vibration. A color video camera using three CCDs (red,...
A measurement system with a temperature control function was developed for mapping the vibration patterns of piezoelectric resonator devices. This system is based on the laser speckle method with intermittent device excitation. By use of a small oven with transparent windows, the vibration shapes of devices can be visualized in high temperature environment. Experimental results using a 5.6 MHz AT-cut...
Our new method solves the limitation of the previous measurement system for in-plane vibration displacement, using two semiconductor lasers with adequately separated wavelengths. Different gammas, that is, interference factors, are determined for each speckle image by using lasers with different wavelengths. The ratio of the two gammas is proportional to the reciprocal of the wavelength ratio of the...
A nonmechanical scanning method has been developed for the visualization of the in-plane mode shapes of piezoelectric devices with polished surfaces. By taking into account the reflection versus laser-wavelength characteristics of the material of the electrodes, the in-plane motion can be measured even if the surface of the measurement plane is polished like a mirror. This method is based on laser...
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