Fiber Grating Design And The Dispersion Characteristics Of The Application

Optical fiber grating (OFG) is a new kind of fast developing device in recent years, which has find wide applications in optical fiber communication. Optical fiber Bragg gratings and other optical communication components based on OFG will play an important role in optical communication systems. The dispersion effect of optical fiber grating is one of the most important characters which not only limits its application range but also become a promising dispersion compensation technology. Chirped fiber gratings offer many advantages including low insertion loss, compactness, cost effective, high dispersion value and the absence of nonlinear effect, thereby showing the most powerful and strong competitive of this dispersion compensation technology.In this thesis, the optical properties of linearly chirped fiber gratings are deeply investigated. Combining the advantages of phase mask and UV beam scanning methods, with a 248nm excimer laser, high quality linearly chirped fiber gratings have been produced.The techniques of fiber grating dispersion measurements have become more and more mature in recent decades. Traditional methods, based on frequency-domain phase-shift modulations and time-domain pulses, have their advantages and disadvantages. In this thesis, we develop an applicable fiber grating dispersion measurement system based on frequency-domain phase-shift method, making it work automatic and programmable. The fundamental theory of frequency-domain phase-shift method is analyzed to educe a numerical method which proposed to process the measured results, result in the improvement of the measurement precision of the time delay ripples.The application of OFG as dispersion compensators for microwave or millimeter-wave fiber-radio systems is still in experimental stage. It may be a new hope to the development of fiber-radio systems even microwave photonics. In this thesis, we discuss the temperature sensing of linearly chirped fiber gratings, which is proposed as the theoretical fundamental of grating group delay variable. The application of linearly chirped fiber gratings as dispersion compensators for microwave or millimeter-wave subcarrier-multiplexed over a fiber link is also demonstrated. The RF power is found recovered after employing linearly chirped fiber gratings. Digital signal with data rate up to 25MHz is modulated over the RF sidebands successfully, achieved a transmission above 35km.