Laser scanning heterodyne-interferometer for micro-components

Laser Doppler vibrometry is a well-established technique for non-contact vi bration measurement. The necessity to monitor the vibration of the whole su rface rather than a single point leads to the appearance of laser scanning vibrometer, However, current scanning vibrometers are applied only to large r structures. Scanning vibrometer for micro-components whose feature size i s in region of millimeters and microns is still under development, and no p rominent achievement obtained until now. In this paper, a novel scanning la ser vibrometry using the combination of acousto-optical deflector and telec entric lens for micro-components is described and the advantages and limita tions of the system are discussed. A scanning vibrometer especially applica ble to micro-components can be developed based on the technique described h ere. Experiments carried out on a diamond-cutting tool and high speed rotat ing rigid disc successfully demonstrate the principle of the system. (C) 20 00 Elsevier Science B.V. All rights reserved.