Title :
Interferometric measurements of displacement on a diffusing target by a speckle tracking technique
Author :
Norgia, Michele ; Donati, Silvano ; Alessandro, Davide D.
Author_Institution :
Dipartimento di Elettronica, Pavia Univ., Italy
fDate :
6/1/2001 12:00:00 AM
Abstract :
Operation of a laser interferometer with a noncooperative target surface, and on a substantial span of displacement (1 m), is reported for the first time to our knowledge. In the paper, we first analyze the errors of an interferometer operating in the speckle pattern regime, then propose the technique of tracking the speckle relative maximum amplitude as a solution for problems so far preventing interferometric measurements of large displacements. Examples of the speckle-statistics improvements are reported. Residual errors are of the order of few wavelengths on a 1-m displacement, indicating that a 10-6-class instrument can be developed. The proposed approach has been implemented with an injection interferometer
Keywords :
displacement measurement; light interferometry; light scattering; measurement errors; statistical analysis; 1 m; 10-6-class instrument; diffusing target; displacement measurement; injection interferometer; interferometric measurements; large displacements; laser interferometer; noncooperative target surface; residual error; speckle pattern regime; speckle relative maximum amplitude; speckle tracking technique; speckle-statistics improvements; tracking; Displacement measurement; Dynamic range; Laser feedback; Optical feedback; Optical interferometry; Optical surface waves; Semiconductor lasers; Speckle; Target tracking; Wavelength measurement;
Journal_Title :
Quantum Electronics, IEEE Journal of
