Study of all-optical routing system

以构建全光路由电路为目标，研究了包括报头提取电路和地址识别电路在内的功能光路。提出了一种新型的全光路。在信头提取电路中，从发送的信元中产生一个控制脉冲，用于整个电路的同步，该控制脉冲附加有起始比特。与传统方案相比，该电路不需要路由表。标题与单元格分离，没有O/E和E/O转换。信元的传输路径由识别出的报头信息决定。为了演示这种操作，我们使用NOLM作为全光开关来构建电路。在头标提取电路中，发射脉冲的宽度和间隔分别为10 nsec和120 nsec。这些仅受本实验中可用设备的限制。可达到的比特率仅取决于光控开关的响应时间，而不取决于电路配置。即使我们使用由2km长的光纤组成的NOLM，对于4psec FWHM的输入脉冲，也可以达到110 Gbps的比特率。在实际应用中，非常需要在低控制功率下工作的具有快速响应时间的光开关。在实验中对4位地址信号进行了成功的验证。

With the aim of constructing all-optical routing circuits, functional optical circuits, which include a header extraction circuit and an address recognition circuit, are studied. Novel all-optical circuits are proposed. Their operation has been demonstrated successfully at a wavelength of 1550nm.In the header extraction circuit, a control pulse, which is used for synchronization throughout the proposed circuits, is generated from the transmitted cell attached with start bits. Comparing with conventional schemes, the proposed circuit needs no routing table. The header is separated from the cell without O/E and E/O conversions. The path through which the cell is transmitted is determined by the recognized header information.In order to demonstrate the operation, the proposed circuit was constructed by using NOLM as all-optical switches. The width and interval of transmitted pulses are 10nsec and 120nsec, respectively, in the header extraction circuit. These are limited only by the facilities available in this experiment. The attainable bit rate is determined only by the response time of optically controlled switch, not by the circuit configuration. Even if we use the NOLM composed of a 2km-long fiber, bit rate of 110Gbps is attainable for input pulse of 4psec FWHM.Optical switches with fast response time, which operate under low control power, are highly desired for a practical application.The signal that controls switches in the routing network is generated in the proposed address recognition circuit. The operation has been successfully demonstrated for 4bit-address signals in the experiment.