Multi-beam heterodyne laser doppler vibrometer

A multi-beam heterodyne vibrometer for analyzing vibration of an object includes an optical system and a combining element. The optical system generates a plurality of object beams and a plurality of reference beams where one of the plurality of beams has a frequency that is shifted from a frequency of the other plurality of beams. The optical system focuses each of the plurality of object beams on the object and transmits the plurality of focused object beams to the object. A portion of each of the plurality of focused object beams is reflected off of a surface of the object as a modulated object beam. The optical system collects the modulated object beams. The combining element combines each of the modulated object beams with a respective one of the reference beams into a plurality of beam pairs.