【摘要】 对光纤失配非对称耦合器中的模式耦合特性进行了理论和实验研究 ,给出了两光纤失配量的临界判据r2 r1 =0 62～ 0 63 ,指出当失配度超过此下限后 ,因出现高阶模的耦合而降低分光比。合理控制失配量 ,研制出分光比为 5× 10 3～ 10 5,损耗为 0 1～ 0 .2dB的光纤零耦合器。更多还原

【Abstract】 The mode coupling characteristic in the asymmetrical coupler is studied theoretically and experimntally. The cirtical fiber mismatch criterion of r 2/r 1=0 62～0 63 is given. It is shown that when the fiber mismatch exceeds the limit, higher order mode coupling occurs and the splitting ratio decreases. By controlling the fiber mismatch properly, the fiber null coupler with splitting ratio of 5×10 3～10 5 and loss of 0 1～0 2 dB is made.更多还原