19 May 2016 Effects of light wavelength and coherence in structured light sensors
Author Affiliations +
Structured light methods are used by many commercial products on the market today. Many such systems using white light projectors while many line gages use standard red laser diodes. However, in recent years there has been much claimed about using blue light, polarized light and partially coherent systems to obtain better performance. Unlike interferometers, moving from red to blue light for a system using only geometric shape information does not gain an automatic advantage from the shorter wavelength. The sensitivity metric does not have a wavelength component to it. But there are other factors that can improve gage performance. The ability to measure some feature is also a function of other parameters such as signal to noise ratio, reflectivity variations, and depth-of-field over which a clear pattern can be seen. This paper will explore the theoretical and experimental data relating to what works and what can be expected from variations on the old methods.
© (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Kevin Harding, Kevin Harding, Rajesh Ramamurthy, Rajesh Ramamurthy, Zirong Zhai, Zirong Zhai, Jie Han, Jie Han, Dongmin Yang, Dongmin Yang, "Effects of light wavelength and coherence in structured light sensors", Proc. SPIE 9868, Dimensional Optical Metrology and Inspection for Practical Applications V, 986806 (19 May 2016); doi: 10.1117/12.2224588; https://doi.org/10.1117/12.2224588

Back to Top