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.
Patent No.:
Date of Patent:
Oct. 07, 2008
Filed:
Oct. 08, 2004
Erlend Ronnekleiv, Trondheim, NO;
Ole Henrik Waagaard, Rondheim, NO;
Kjell Blotekjaer, Trondheim, NO;
Dag Thingbo, Vikhammer, NO;
Sigurd Lovseth, Trondheim, NO;
Sverre Kundsen, Trondheim, NO;
Erlend Ronnekleiv, Trondheim, NO;
Ole Henrik Waagaard, Rondheim, NO;
Kjell Blotekjaer, Trondheim, NO;
Dag Thingbo, Vikhammer, NO;
Sigurd Lovseth, Trondheim, NO;
Sverre Kundsen, Trondheim, NO;
Optoplan AS, Trondheim, NO;
Abstract
Methods and apparatus reduce coherence of an optical signal that is used to interrogate optical interferometric sensors. The optical field phasor of the interrogation source is modulated in a controlled manner to produce a broadened optical source power spectrum at the output of the source unit. The output from the source unit is launched into an optical sensor network, comprising a multiple of optical pathways from its input to the detection unit, where pairs of optical pathways form sensor interferometers. A compensating interferometer with delay difference similar to the sensor delay difference may be arranged in a serially coupled manner with the optical sensor network, either before or after the network. The coherence modulation may be performed through direct modulation of the source or through external modulation of the light with piezoelectric ring modulator, a Lithium niobate phase or intensity modulator, or an acoustooptic modulator.