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Illustration Fiber optic sensor

The optical fibre can be used as a distributed sensor by exploiting light scattering effects or as a quasi-distributed sensor network by functionalizing the fibre through Bragg gratings photo-inscription for instance. In this case, a laser is used for creating a periodic modulation of the fibre optic refractive index. This grating will have optical reflection and transmission properties that can be influenced by external effects like temperature or mechanical strains applied on the fibre. As a consequence, the optical fibre can be used as an ultra sensitive multi-points sensor.

fibre optic sensor

Fibre optic sensors applications

Multitel develops full solutions for different applications:

  • Temperature and stain measurements for structural health monitoring (by externally fixed or embedded sensors into composite materials for instance)
  • Biochemical detection based on long period gratings and/or functionalization of the optical fibre (exploitation of plasmonic effects)
  • Patient health monitoring by a smart textile with embedded fibre sensors.


Fibre sensors for railway applications
Fibre optic sensors for railway monitoring applications


Structural health monitoring
Monitoring of the structural integrity of a boat mast


Smart textile for healthcare
Smart textile with MRI compatible embedded fibre sensor

Fibre Bragg Gratings fabrication

Phase mask FBG inscription
Inscription of a Fibre Bragg Grating by phase mask technique

In function of the targeted application, Multitel can realize different types of fibre Bragg gratings on various types of fibred by using adapted techniques:

  • Fibre Bragg Gratings fabrication by UV phase masking technique
  • Point by point photo-inscription by femtosecond laser
  • Realisation of long period gratings
  • Through the cladding inscription

Custom Interrogation Systems

MULTITEL can develop the most adapted interrogation system for a given application, depending on its specific needs like flexibility, robustness, low cost and/or high speed measurements. MULTITEL realized such systems for various application fields with very different technical and environmental constrains like in medical or railway domains.

Respiratory rate FBG reader
Breathing frequency reader based on a fibre Bragg grating sensor.
Strain sensors interrogator
Interrogator for strains monitoring