模耦合与双折射对NOLM开关特性的影响

Effect of Mode Coupling and Birefringence on NOL M Optical Switching

从光耦合器的耦合方程出发 ,全面分析了光耦合器与环路光纤的模耦合与双折射对NOLM开关特性的影响。研究表明 ,在耦合器为弱耦合条件下 ,环路光纤的模耦合和耦合器的分光比是影响NOLM开关效率和消光比的最重要的因素。只要环路光纤的模耦合角为零 ,分光比为 1:1,其他因素的影响均可忽略。若要求消光比优于 10dB ,环路光纤的耦合角应小于

Based on the coupling equation of an optical coupler, the effect of mode coup ling and birefingence of the coupler and loop fiber o n switching characteristics is discussed in detail.The results show that,in the condition of weakly cou pling of the coupler,the coupling angle of loop fiber and coupling ratio of the coupler are the most important of all factors.As long as the coupling angle of l oop fiber is equal to zero,and coupling ratio of the coupler is equal to 1:1,oth er factors can be neglected.If the extinction ratio is better than 10 dB,the cou pling angle of loop fiber should be less than 4°.