Experimental Research Of Alloptical Switch Based On Fiber Resonater Containing EDFA

With the rapid development of the network of optical fiber communication, In the present optical network, the switching between optical signals still use the electronic devices, which has a slow speed. It restricts the further enhancement of data processing speed and extremely blocks the development of optical network. It is so called "electronics bottleneck". Using all-optical switches in optical network is an effective way to solve the problem of "electronics bottleneck". All-optical switches have many advantages: high speed, huge capacity, high reliability and without O-E-O conversion. All-optical switches can be used in broadband multimedia communication, and for reducing the cost of network.The structure of the double fiber coupler ring resonator all-optical switch is simple, it can be integrated easily; it can also be easily coupled with fiber network, and the insertion loss of it is quite small. Owing to the great potential of the double fiber coupler ring resonator all-optical switch, it becomes one of the hot research subjects.In this thesis, we mainly study on the double fiber coupler ring resonator all-optical switch containing an EDFA, and analyze this kind optical switch principle in details. By using the fiber weak coupled-mode theory, we also analyze what a role the EDFA plays. We calculated and analyzed the switching properties of the ring switches in the cases without loss and with loss. We find that it is hard to realize the switching in the device with loss in the ring. When we insert an EDFA in the ring, the switching power can be reduced rapidly and the switching rate can be increased, however, the switching time will be increased at the same time. By controlling the gain of the EDFA, the reflectivity of couplers or other parameters, we can make a tradeoff between the switching power and the switching time to obtain the desired switching parameters. For example, we can obtain the switching power down to several mW, the switching time can be controlled below several hundred ns.Based on the theoretical works, we made the experiments for proving the theory. When inserting the experimental data into the theoretical formula to calculate the switching power, we can get the switching power is several hundred μW only.Finally, we introduce a feasible experiment. The switching can be realized by controlling the pump power of the EDFA, while the ring is not at the resonance. We can obtain the switching rate about seventy percentage. We also discussed that the influence of the output power ratio of the fiber coupler and the input power etc. to the switching properties.