This paper reports the progress of the 863 high-technology project of China "Optical Resilient Packet Ring (O-RPR) Based on All-optical Buffering Techniques". In this ring network, for the packet through an intermediate node the conversion of O/E/O is not needed in order to overcome the bottleneck of O/E/O. In all-optical node a Dual Loop Optical Buffer (DLOB) is used to revolve the collision between the packet, which pass through the node, and add packet from local user to ring. The principle of DLOB is introduced. The bit-rate of head of optical frame is lower than the bit-rate of payload in a packet, in order to increase the efficiency of transmission link. This paper will introduce the network topology, layers and the structure of optical node. It includes an optical splitter, optical delay line as input buffer, a SOA as optical switch, which switch the packet dropping down form the ring or pass through the node, a DLOB and an electric buffer. An ARM is used for regulation of different buffers. The experiment results of a demonstrate network including 3 nodes are given.
Optical buffers are critical for low packet-loss probability in future photonic packet-switched networks. In particular, they would be required to store packets during rate conversion and header processing, and to overcome the receiver's bottleneck. They would be required for queuing packets while transmitters await access to the network.
In this paper, we present a novel structure of optical buffer with compact size. This kind of optical buffer is based on a collinear 3x3 fiber coupler in which three fibers are completely in the same plane and weakly coupled. A SOA is used as its nonlinear element as well as an amplifier in it.The experiment result will be also given in the paper. Storage results obtained with this novel structure optical buffer at 100Mb/s will be presented first and then its capacity is extended to higher data rates of 2.5Gb/s, more compatible with present optical networks. Storage has been observed for time up to 1.568ms(more than 32 circulations) in both cases without obvious degration.
The novel structure of optical buffer could be a more compact device which makes it possible to be integrated in a chip. SOA in the buffer is used as a nonlinear element as well as an amplifier to compensate loss in the buffer loop. The buffer needs low control power for switch operation. It is easy to control 'write' and 'erase' operation because the same TOAD switch in the buffer can be used for both 'write' and 'erase' operation.