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Optical Engineering • Open Access

Displacement sensor based on optical feedback interferometry in a GaN laser diode
Author(s): Jukka T. Hast; Leszek Krehut; Risto A. Myllylä

Paper Abstract

We describe an optical displacement sensor based on optical feedback interferometry in a blue-light emitting GaN laser diode. Also presented are preliminary results from measuring variations in the optical path length (OPL) of an external cavity (EC) in the 0- to 240-nm range. These results show that, within the specified range, the sensor follows linearly the OPL variation of the EC. Moreover, the slope between a reference and the measured OPL is 1.0003, and the average deviation from the linear slope is 5 nm in this range. Finally, we also consider the stability of the interference signal in long-term measurements.

Paper Details

Date Published: 1 August 2005
PDF: 2 pages
Opt. Eng. 44(8) 080504 doi: 10.1117/1.2010167
Published in: Optical Engineering Volume 44, Issue 8
Show Author Affiliations
Jukka T. Hast, Univ. of Oulu (Finland)
Leszek Krehut, Univ. of Oulu (Finland)
Risto A. Myllylä, Univ. of Oulu (Finland)


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