Wavelength-scanning Talbot effect and its application for arbitrary three-dimensional step-height measurement |
| |
Authors: | Satish Kumar Dubey Amitava Roy |
| |
Affiliation: | a Laser Applications and Holography Laboratory, Instrument Design Development Centre, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110 016, India b SERC Division, Department of Science and Technology, New Delhi, India |
| |
Abstract: | We demonstrate the phenomenon of Talbot self-image plane shift by tuning the wavelength of the broadband light source. A superluminescent diode (SLD) is used as a broad-band light source and an acousto-optic tunable filter (AOTF) as wavelength-scanning device. A periodic grating is illuminated by the wavelength tuned light of SLD using AOTF and Talbot self-image plane is shifted continuously in the longitudinal direction without mechanically moving the grating. The wavelength-scanning Talbot effect is then implemented for the measurement of arbitrary step-height of discontinuous objects with extended range. The main advantages of the proposed system are non-mechanical scanning, high stability because of it’s common-path geometry and compactness. Since the measurement of the phase is not required the system is free from phase ambiguity problem and therefore, the range of measurement is large as compare to interferometric techniques. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |
|