Optovláknový senzor teploty s využitím EDFA zesilovače

Abstract

This dissertation deals with the development of a new type of fiber optic temperature sensor, based on an interferometer in combination with an erbium doped fiber amplifier. The first part describes currently available technologies for temperature measurement along with their parameters and functionality. The following chapter deals with interferometers and, apart from explaining the phenomenon of light interference itself, it presents individual types of interferometers, their connection schemes and an evaluation of basic properties. The third part is dedicated to the analysis of the technology of erbium doped fiber amplifiers and introduces literature retrieval on connecting fiber amplifiers and sensors whose key feature is thermal instability. The fourth part presents a design of the new temperature sensor, the main parts of which are a method of integrating the EDFA amplifier into the interferometer, a choice of the doped fiber length, an analysis of all used components and a description of the measuring station with the testing set. The final part of the work is dedicated to the analysis and experimental verification of the designed and constructed temperature sensor. Various pumping laser settings and different pumping directions are tested, using two types of fibers with different erbium ion content. At the very end the range of the sensor and the signal-to-noise ratio are analysed. An important part of the work is a design of a method for obtaining the phase shift to degrees Celsius conversion characteristic. The output is a comprehensive design of a new type of temperature sensor that achieves excellent sensitivity.