Real-time Micro-vibration Measurement Based on Digital Holographic Interferometry

An experimental system based on digital holographic interferometry is proposed for real-time high-precision micro-vibration measurement. Vibration information can be extracted directly and instantaneously from the holograms by using the fast micro-vibration testing algorithm. As the received light of the proposed system is scattered beam, no assumption is made on the object surface. Unlike other optical detection approaches, the proposed method can detect plane vibration rather than point vibration without any assumptions on object surface feature and receiving angle. The feasibility of the proposed system is demonstrated by using a vibrating object driven by standard sinusoidal signal.