In this Ph.D. thesis a high-performance fiber Bragg grating fabrication system is presented. Fiber Bragg gratings are currently key components in modern optical communications systems, enabling the implementation of nearly all optical signal processing devices, when properly designed. High-performance is used in this thesis to refer to a research-oriented fabrication system meant to be versatile. The fabrication system is able to produce nearly whatever fiber grating the system research users can conceive, with quality comparable to the most modern commercial systems. Along this Ph.D. thesis the fiber Bragg grating fabrication system built within the Optical and Quantum Communications Group at UPVLC is described, detailing components, functioning and performance. A theoretical background upon the system is built is presented too. Moreover, a theoretical model of fiber Bragg gratings regarding their polarization properties (polarization dependent loss, differential group dealy and Stokes parameters), along with the experimental proof, is developed. The relevance of this study to fiber Bragg gratins applications to telecommunications and sensing is revealed. The thesis presents the use of fiber Bragg gratings for sensing applications, showing: practical examples for mechanical stress determination on concrete and stainless steel structures; the development of a multiple parameter sensor (stress, temperature, humidity, pH), to evaluate damage suffered on these structures; the design of a sensor based on phase differences between fiber Bragg gratings; and the design of a monitoring system able to query a large number of sensing devices, by means of fiber Bragg gratings and conventional fiber optics components. Finally, telecommunication applications are shown, in the fields of optical processing of microwave signals, the detection of phase-modulated optical signals and in optical code division multiple access systems.