Dynamic measurement of micro-components by image-plane digital holography

• Main Authors: Fu, Yu, Shi, Hongjian, Quan, Chenggen, Tay, Cho Jui
• Other Authors: International Conference on Experimental Mechanics (2008 : Nanjing, China)
• Format: Conference or Workshop Item
• Language: English
• Published: 2010
• Subjects: DRNTU::Science::Physics::Optics and light
• Online Access: https://hdl.handle.net/10356/79244; http://hdl.handle.net/10220/6479
• Institution: Nanyang Technological University

A method for whole-field non-contact measurement of displacement, velocity and acceleration of a vibrating microobject based on digital holographic microscopy is presented. A micro-beam is excited by a fluctuating voltage with a sinusoidal configuration. A series of digital holograms are captured using a digital holographic microscope with a highspeed camera. The result of reconstruction is a three dimensional complex-valued matrix with noises. In this paper, Fourier analysis and windowed Fourier analysis are applied in both the spatial and temporal domains to extract the kinematic parameters. The instantaneous displacement is obtained by temporal phase unwrapping of the filtered wrapped phase map, while the velocity and acceleration are evaluated by windowed Fourier analysis along the time axis. The combination of digital holographic microscopy and temporal Fourier analyses is able to study the vibration without a phase ambiguity problem, and the instantaneous kinematic parameters on each point are obtained.