Open AccessLaser-self-mixing interferometry in the Gaussian beam approximation: experiments and theory
Author(s) -
Francesco De Lucia,
M. Putignano,
Simona Ottonelli,
M. di Vietro,
Maurizio Dabbicco,
Gaetano Scamarcio
Publication year - 2010
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.18.010323
Subject(s) - optics , physics , collimated light , m squared , gaussian beam , beam parameter product , gaussian , laser , beam (structure) , interferometry , laser beam quality , beam diameter , wavefront , plane wave , laser beams , quantum mechanics
We analyze the laser-self-mixing process in the Gaussian beam approximation and reformulate the expression of the feedback coefficient C in terms of the effective feedback power coupled back into the laser diode. Our model predicts a twenty-fold increase of the ratio between the maximum and the minimum measurable displacements judged against the current plane-wave model. By comparing the interaction of collimated or diverging Gaussian laser beams with a plane mirror target, we demonstrate that diverging beams tolerate larger wobbling during the target displacement and allow for measurement of off-axis target rotations up to the beam angular width. A novel method for reconstructing the phase front of the Gaussian beam by self-mixing scanning measurements is also presented.