Fiber Bragg Gratings in Temperature and Strain Sensors

Abstract: ROYAL INSTITUE OF TECHNOLOGY Abstract Laser Physics Group Department of Applied Physics SA104X Degree Project in Engineering Physics, First Cycle Fiber Bragg Gratings in Temperature and Strain Sensors by Ilian Haggmark Supervisor: Michael Fokine A Fiber Bragg Grating (FBG) is a periodic variation of the refractive index in an optic ber. It works as a wavelength selective lter and is used in several dierent applications such as telecommunication and sensor technology. Fiber sensors are based on a simple principle; the ber is aected by strain, temperature etc. due to which the selection of wavelengths in the FBG change. With an optical spectrum analyzer the changes in wavelength reection can be observed and converted to the physical quantity measured. In this thesis the properties of FBGs used in temperature and strain sensors are tested. Experiments to improve the precision of the sensors by embedding FBGs in metal are also carried out.