Optical Properties Of Amplitude Sampled Fiber Gratings Fabricated By Splicing Technology

ABSTRACT:Due to the low efficiency of pure amplitude sampled fiber gratings, the grating length should be greatly increased for obtaining high reflection sampled gratings. A splicing technology, which can be used to fabricate high-reflectivity amplitude sampled fiber gratings, is presented in this paper. The influence of the splicing errors and the splicing times on the reflection spectrum performance of rectangle-sampled gratings is analyzed in details.In this thesis, the optical characteristics of splicing rectangle-sampled fiber gratings are analyzed under different splicing times and splicing errors. The main works are as follows:(1) The coupled-mode equations for uniform and linear chirped gratings and its numerical implementation methods are described in details, based on which, the effects of various parameters on the spectra characteristics of fibers gratings are analyzed.(2) According to the coupled-mode equation of uniform grating and the transmission matrix of linear chirped grating, the numerical implementation methods are also analyzed in details. Then, the various parameters of sampled gratings, including uniform sampled gratings and sampled chirped gratings, are simulated and studied.(3) The major contribution of the thesis is that a splicing technology for the fabrication of high reflection sampled gratings was proposed and analyzed. Both the splicing uniform sampled grating and the splicing sampled chirped grating are studied and simulated with the effects of splicing times and splicing errors as the focal points.(4) Based on above studies, the splicing errors tolerances are determined when the length of spliced uniform sampled gratings is 20cm and 30cm. And the splicing errors tolerances are also determined when the length of spliced sampled chirped gratings is 20cm. The primary results are as follows:1) When the length of spliced uniform sampled gratings is 20cm, the splicing error tolerance is (-0.1,0.1)μm for 3 time splicing; the splicing error tolerance is (-1,1)μm for only one time splicing. When the length of spliced uniform sampled gratings is 30cm, the splicing error tolerance is (-0.1,0.1)μm for 2 or 5 time splicing.2) When the length of spliced sampled chirped gratings is 30 cm, the splicing error tolerance is (-0.001,0.001)μm for 1 or 2 time splicing. And the delay properties will be worse as the splicing error increases.