Multiple Fibre Bragg Grating Force Sensor

Abstract: The purpose of this project is to explore the FBG (Fiber Bragg Grating) technology and create a force sensor. The result can be used as a basis for further projects.The project starts with force and strain measurements. The project then evolves to incorporate multiple FBG sensors. An uncommon method of writing the FBG withcoating is tested, which results in a FBG with most of the coating left.The result is a multi-FBG sensor. And even though the individual FBG is not linear the sum shows fantastic linearity with R-square of 0.99999. The change in wavelength is 1328pm/N. A common issue in the strain measurement is discussed and proof is provided. This shows that the reference value of the FBG is 1.12pm/μstrain instead of 1.21pm/μstrain. This is important if the FBG is mounted in a structure, because then the material proprieties will be dominating. Another result is that the peaks of Fabry Perot grating pair are linear but with different coecients.