Modelling and record technologies of address fiber Bragg structures based on gratings with two symmetrical pi-phase shifts

Abstract

Address fiber Bragg structures (AFBS) make it possible to effectively solve the problems of interrogation and multiplexing of sensors in multi-sensor networks with microwave photonic processing of information. Based on a complex method of transmission matrices and the coupling of directional modes, a mathematical model was constructed to determine the spectral profile of a fiber Bragg grating (FBG) with two discrete symmetric phase π shifts and parameters of 2π-FBG AFBS based on them. Based on the study of the mathematical model, the possibility of selecting the necessary parameters of 2π-FBG AFBS is shown, which allow forming its spectral profile in such a way that the specified structure can be used as a sensitive element of the sensor and provides the necessary linear displacement in the optical range and preserves the required frequency separation between discrete symmetric phase shifts location in the radio frequency range. The analysis of the formation and recording methods for 2π-FBG AFBS was carried out. To implement given structures, the technology, using of an ultraviolet argon laser, the classic phase masks with sequential recording of several arrays with precise movement of the fiber were chosen.