Gain Of The Wide-angle Optical Splitter

Because of the high-speed development of the Optical Communication Technology, much more attention is paid to the investigation of splitters with amplification. The splitter with amplification is the integratation of the amplifier and passive splitter. Compared to fiber amplifier and fiber splitter, it has lower cost, higher flexibility and higher condensity, and it's very suitable for the applications in optical communication. The branching angle of traditional splitter is very small, making the device too long and hard to perform technical integration. So, it is of practical significance to study the wide-angle splitter with amplification.At first, the international new development of the low-loss wide-angle branch and splitter with amplification is introduced. Finite-defference beam propagation method (FD-BPM) in the analysis of optical waveguides is investigated, especially the new development of the wide angle 3D FD-BPM, and its algorithm formulations are developed. Then, the algorithms of both 2D and 3D FD-BPM are programmed with Matlab language, and the wide-angle propagation of optical field is taken as example to verify the program that is written.The low-loss wide-angle Y-branch with microprisms is intvestigated by using of the principle of phase conpensation, and a new low-loss wide-angle three-branch optical waveguide with equal power division is proposed according to the Snell's law. Different wide-angle branches with microprisms are numerically simulated and analyzed by the wide-angle FD-BPM program that is written. After that, the wide-angle splitter that is composed by wide-angle Y-branch and bends is numerically simulated. The result demonstrates that it is possible to construct wide-angle low-loss waveguide beamsplitter using microprisms in theory.Semi-vectorial Finite-defference mode solver algorism is also programmed to simulate the optical field in LiNbO3 waveguide that is made by Ti diffusion and annealed proton-exchange method. The overlap integral method is used to investigate the gain characteristic of Er-diffusion doped Ti:LiNbO3 waveguide amplifier and lithium niobate proton-exchang waveguide amplifier in which Erbium is doped by the ion exchange process, and the simulation result demonstrates that Erbium dopping by the ion exchange process can increase the overlap integral between optical field and Erbium ion distribution, and therefore make a significant improvement of the optical gain.At last, the whole structure of the wide-angle splitter with amplification is designed, and the experiment of the Er-doping by ion-exchange process in LN is performed.