Absolute angle measurement using dual-wavelength laser speckle: theory and method
dc.contributor.author | Gibson, Sam J. | |
dc.contributor.author | Charrett, Thomas O. H. | |
dc.contributor.author | Tatam, Ralph P. | |
dc.date.accessioned | 2024-01-04T15:50:22Z | |
dc.date.available | 2024-01-04T15:50:22Z | |
dc.date.issued | 2023-11-30 | |
dc.description.abstract | This paper presents a method utilising the speckle pattern formed by dual-wavelength illumination for the measurement of the two out-of-plane surface angles with respect to the sensor frame. Theoretical expressions are derived relating the observed speckle shift between patterns formed by two wavelengths for tilted surfaces with both on-axis and off-axis detector positions. These expressions are verified experimentally, showing RMS errors of between 0.5–1.0 . Finally, an on-axis implementation of the concept is presented using dual-wavelength illumination generated from two modes of a standard FP diode laser. Simplified expressions for the calculation of surface angles from measured speckle shift using this arrangement are presented, given in terms of three sensor constants; the responsivity or sensitivity of the sensor, C, and the zero surface tilt speckle shifts, Ax0 and Ay0. Experimental results using this sensor for a range of surface tilts between 0.0° and 7.5° showed an RMS error of 0.10° in θx and 0.19° in θy. | en_UK |
dc.identifier.citation | Gibson SJ, Charrett TO, Tatam RP. (2024) Absolute angle measurement using dual-wavelength laser speckle: theory and method. Optics and Lasers in Engineering, Volume 174, March 2024, Article number 107956 | en_UK |
dc.identifier.issn | 0143-8166 | |
dc.identifier.uri | https://doi.org/10.1016/j.optlaseng.2023.107956 | |
dc.identifier.uri | https://dspace.lib.cranfield.ac.uk/handle/1826/20608 | |
dc.language.iso | en | en_UK |
dc.publisher | Elsevier | en_UK |
dc.rights | Attribution 4.0 International | * |
dc.rights.uri | http://creativecommons.org/licenses/by/4.0/ | * |
dc.subject | Laser speckle theory | en_UK |
dc.subject | Absolute angle measurement | en_UK |
dc.subject | Dual-wavelength speckle | en_UK |
dc.title | Absolute angle measurement using dual-wavelength laser speckle: theory and method | en_UK |
dc.type | Article | en_UK |
dcterms.dateAccepted | 2023-11-19 |