The present disclosure relates to optical fibers having fiber Bragg gratings, sensing devices using the same, and methods for providing and using said fibers and devices.

TYPE OF DEVELOPMENT

Twin core fiber, supermodes, fiber Bragg grating, vibrations sensor.

DESCRIPTION

An optical fiber includes a first single mode fiber and a second fiber. The first fiber has a core extending between its ends. The second fiber features two cores, the first core aligned with the central axis of the fiber, allowing optical coupling with the first fiber at one end, while the second core remains unconnected. Both cores comprise fiber Bragg gratings with identical reflection wavelengths, extending the same length and positioned equidistant from the first end.

INDICATION

The device can be used in diverse sensing applications. For example, it can be used to monitor:

• Bending or curvature and the direction of the same.
• Vibrations as they can be converted to periodic changes of bending or curvature.
• Temperatures as FBGs are sensitive to it.

NOVELTY/ADVANTAGE

• In the present invention, a twin coupled-core fiber TCF is fusion spliced to a conventional single mode optical fiber (SMF). The FBG is inscribed in the TCF with standard procedures. In this manner, the interrogation of the grating is simplified.
• Relative intensity changes of the FBG can be monitored with an inexpensive system as there is no need to track wavelength changes, besides no fan-in/ out devices are required.
• It is well known in the art that the position of the Bragg wavelength changes with temperature, but the intensity of the grating does not change with temperature. Thus, a single grating inscribed in a TCF can provide information about temperature and bending degree and direction of the bending.

INFORMATION

• Reference: Bragg Device
• Research group: Applied photonics group (APG)
• Main researcher: Agustin Joel Villatoro Bernardo
• Contact: Knowledge/Technology Transfer Office, iproperty.otri@ehu.eus

IPR STATUS

• Patent filing: EP22727852 (Pending)
• Priority date: 04/05/2021
• Applicant: University of the Basque Country / Polytechnic University of Valencia

COOPERATION GOAL

License agreement.