Abstract: A multi-beam laser Doppler vibrometer simultaneously measures velocity, displacement, and vibration history of multiple locations on an object. A beam of coherent light is split into an object beam and a reference beam. The object beam is divided into a plurality of object beams to simultaneously illuminate multiple locations on the object under inspection. The reference beam is frequency shifted and split into a corresponding plurality of frequency-shifted reference beams. A portion of each object beam is reflected by the object as a modulated object beam. The plurality of modulated object beams are collected and respectively mixed with the plurality of frequency-shifted reference beams to provide a plurality of beam pairs. Each beam pair may be focused onto a photodetector or an optical fiber connected to a photodetector.
Type:
Grant
Filed:
October 31, 2005
Date of Patent:
October 3, 2006
Assignee:
MetroLaser
Inventors:
Amit K. Lal, Cecil F. Hess, Hansheng Zhang, L. Ernesto Hurtado, Vladimir B. Markov, Vyacheslav Aranchuk