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Development of a two-dimensional optical accelerometer using a DVD pick-up head

This study develops a low-cost, highly sensitive two-dimensional optical accelerometer based on a commercially available DVD optical pick-up head. Vibrations of the structure of interest cause a change in the angle of the seismic mass within the accelerometer. The relative movement between the seismic mass and the base produces a change in the distribution of a focused light spot on the surface of a four-quadrant photodetector. The resulting change in the voltage signals output by the photodetector is then used to calculate the corresponding acceleration of the base. The experimental results indicate that the sensitivities of the accelerometer in the X- and Y-axis directions are 22.9 V/g and 21.3 V/g, respectively.