Abstract
<jats:p>The subject of the monograph is the measuring the rotation angle of the polarisation plane of light propagating through an optical fibre. The measurement system employs a tilted Bragg grating as the element sensitive to changes in the polarisation plane’s rotation angle. The spectrum of the light transmitted through the grating is recorded using a spectrum analyser and subsequently processed numerically to compute the rotation angle. An analysis of the feasibility of applying a discrete wavelet transform (DWT) to convert the measured light spectrum into the rotation angle of the polarisation plane is presented. The author introduces, implements, tests, and discusses a method for determining the light polarisation plane rotation using a discrete wavelet transform, demonstrating the effectiveness of the proposed approach for the studied application. The first part of the monograph provides a detailed description of the working principles of Bragg gratings, including a discussion of their various types. Additionally, methods for the production of Bragg gratings are presented, along with a description of the gratings fabricated for this research. The second part focuses on measuring the rotation angle of light’s polarisation plane. It reviews the urrent state of the art in this area and describes the laboratory setup employed during the research.The properties of the discrete wavelet transform are analysed concerning their potential applicability in ongoing research. Based on this analysis, an original method for measuring the angle of rotation of light’s polarisation plane using a discrete wavelet transform is proposed. The monograph demonstrates that it is feasible to measure the rotation angle of the polarisation plane of light propagating in optical fibre within the range of 0° to 180°, and that a discrete wavelet transform can be successfully applied to perform the necessary calculations.</jats:p>