Multipoint heterodyne vibrometry for measurements on unstable biomedical objects
Faculty of Sciences. Physics
Eighth International Symposium on Laser Metrology: Macro-, micro-, and nano-technologies applied in science, engineering and industry
8th International Symposium on Laser Metrology, FEB 14-18, 2005, Merida, MEXICO
, p. 314-324
University of Antwerp
In unstable objects, such as biological specimens, vibrational patterns can change quickly with time. To determine phase relationships between several vibrating points in such an object, it is therefore necessary to measure those points simultaneously. We describe a dual channel heterodyne interferometer capable to acquire vibrational data at two arbitrary spatial points simultaneouly over the entire acoustic frequency range. The design allows extension to four or even eight independent channels. Channel cross-talk is measured to be about -30 dB, below the S/N ratio within the signal channel. Velocity resolution is estimated to be 10 mu m/s, corresponding to an amplitude resolution of 1.5 nm at 1 kHz.