Characterisation of an electronic speckle pattern interferometry with active wavefronts

• Main Author: Joshi, Amita
• Other Authors: Min Lu
• Format: Theses and Dissertations
• Language: English
• Published: 2018
• Subjects: DRNTU::Engineering::Electrical and electronic engineering
• Online Access: http://hdl.handle.net/10356/73102
• Institution: Nanyang Technological University

Electronic-Speckle-Pattern-Interferometry (ESPI) is a versatile technique for shape measurements of rough surfaces. The ESPI is limited by two effects: the diffraction on sharp edges and the 2π-modulo-periodicity based on the interferometric principle. Thus, this method is restricted to smooth surfaces with small height variations respective the used synthetic wavelength. To extend the measurement range to complex surface structures, the reference wavefront of the ESPI-setup will be adapted to the measurement object by a liquid crystal modulator. In this study, an automated process for the measurement of surface shapes with active wavefronts shall be developed. This includes the controlling of the system parameters, the image recording and the data processing. Based on these findings, the system will be tested and characterized.