Laser-diode interferometric heterodyne vibrometer: application to linear motor control

We describe an interferometric heterodyne vibrometer that uses a laser diod e with a triangular modulation frequency. This optical sensor is used to pr obe a vibrating polished surface. As an illustration of the sensor performa nce, the control of nonuniform velocity of a linear motor is achieved. The technique can be used over a large bandwidth between a few hertz and severa l tens of kilohertz. Generalization of the technique to the sensing of freq uency vibrations is also demonstrated theoretically. (C) 2001 Optical Socie ty of America.