The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Aug. 08, 2017

Filed:

Oct. 15, 2014
Applicant:

Universitat Politècnica DE Catalunya, Barcelona, ES;

Inventors:

Santiago Royo Royo, Castellbisbal, ES;

Francisco Javier Azcona Guerro, Terrassa, ES;

Ajit Jha, Terrassa, ES;

Assignee:
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
G01B 9/02 (2006.01); G01S 17/32 (2006.01); G01S 17/58 (2006.01); G01B 11/02 (2006.01); G01S 7/491 (2006.01);
U.S. Cl.
CPC ...
G01B 9/02092 (2013.01); G01B 9/02004 (2013.01); G01B 9/0207 (2013.01); G01B 11/026 (2013.01); G01S 7/4916 (2013.01); G01S 17/32 (2013.01); G01S 17/58 (2013.01);
Abstract

A method and system to implement the method of measuring a change in an optical path length using differential laser self-mixing interferometry. The method includes obtaining a reference SMI signal (Sr) and a main measurement SMI signal (Sm) of a laser (LD) and determining the relative change in the optical path length between the (LD) and a target (T) in a range between 0 and λ/2, by comparing the relative positions along time of fringes or transitions of the (Sm) and (Sr). The (Sr) and the (Sm) are obtained at different moments once backscattered laser light (br) is generated from the reflection on said target (T) of a reference and a main measurement laser light beam emitted by the laser (LD) and while being modulated according to a specific modulation pattern that maintained while both the (Sr) and the (Sm) are acquired and has re-entered its laser cavity.


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