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电路。提出了新型全光电路。他们的工作已经在1550nm的波长上成功地进行了演示。在报头提取电路中，从带有起始位的传输单元产生一个控制脉冲，该脉冲用于在所提出的电路中进行同步。与传统方案相比，该电路不需要路由表。标题与单元格分开，没有O/E和E/O转换。传输单元的路径由已识别的报头信息决定。为了演示该电路的操作，我们采用NOLM作为全光开关来构建电路。在报头提取电路中，传输脉冲的宽度和间隔分别为10nsec和120nsec。这些仅受限于本实验中可用的设备。可达到的比特率仅由光控开关的响应时间决定，而不受电路配置的影响。即使使用由2公里长的光纤组成的NOLM，输入脉冲为4psec频宽时，也可以达到110Gbps的比特率。光开关具有响应时间快、控制功率低的特点，在实际应用中是非常需要的。控制路由网络中的交换机的信号在所提出的地址识别电路中产生。该方法已在实验中成功地应用于4位地址信号。

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.