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1.
In this paper, an inner wavelength method is proposed to enlarge buffering capacity of shared fiber delay line buffers. In addition, an optical packet switch called extended shared buffer type optical packet switch(extended SB-OPS) is proposed to realize the inner wavelength method. In order to further improve performance of extended SB-OPS, a greedy algorithm based on inner wavelength method is introduced.The performance of extended SB-OPS is evaluated by simulation experiments.  相似文献   

2.
A simple and accurate method for calculating the optimal width of an annular spiral phase plate (SPP) to generate optical vortices with sidelobe suppression is proposed. The sideloSes can he sharply suppressed when the ratio of inner and outer radii of an annular SPP is equal to that of the principal ring and the first sidelobe diffracted by a circular SPP with the same topological charge n. Moreover, the ratio of the inner and outer radii of the optimal annular SPP depends only on the topological charge n and is not affected by the incident wavelength or the size of the SPP.  相似文献   

3.
We propose a novel ring resonator configuration in a channelless photonic crystal. The proposed ring resonator utilizes the self-collimation effect and the bending and splitting mechanisms of line defects to route the propagation of light, instead of conventional indexed-guided waveguides or photonic crystal band gap waveguides. The finite-difference time-domain method (FDTD) is used to investigate the characteristics of the ring resonator. The new design exhibits an ON--OFF contrast with an extinction ratio of more than 12dB, and has an ultra-compact footprint of 3.3×3.3μm2 when it operates at the optical communication wavelength λ=1.55μm. The design presented may find applications in the areas including ultra-compact optical switch and wavelength filer in integrated optical circuits.  相似文献   

4.
This letter describes a novel optical method for wavelength fine-selection in the optical spectrum analysers (OSAs) for dense wavelength division multiplexing (DWDM) applications. The proposed new method employs a 'refractive optical lever' system consisting of a rotating optical wedge prism. A new OSA system based on Littman-type monochromator is proposed and the wavelength selection accuracy and resolution of OSA that has included such an optical lever system have been improved by a factor of 20 to 100 depending on the wedge angle and offset orientation angle of the optical wedge prism. This proposed 'refractive optical lever' may also simplify the rotation mechanism of the mirror in the commercially available OSAs.  相似文献   

5.
An optical cross connection network which adopts coarse wavelength division multiplexing (CWDM) and data packet is introduced. It can be used to realize communication between multi-CPU and multi-MEM in parallel computing system. It provides an effective way to upgrade the capability of parallel computer by combining optical wavelength division multiplexing (WDM) and data packet switching technology. CWDM used in network construction, optical cross connection (OXC) based on optical switch arrays, and data packet format used in network construction were analyzed. We have also done the optimizing analysis of the number of optical switches needed in different scales of network in this paper. The architecture of the optical interconnection for 8 wavelength channels and 128 bits parallel transmission has been researched. Finally, a parallel transmission system with 4 nodes, 8 channels per node, has been designed.  相似文献   

6.
Optical packet switching (OPS) technology can rapidly deliver the enormous network bandwidth and offer high-speed data rate and format transparency. In this paper we propose a novel architecture using all-optical tunable wavelength converters (TWCs) and fiber delay-lines (FDLs) to address the contention problem for OPS in wavelength and time domains. This architecture improves packet switching speed but significantly decreases the number of optical switches comparing with existing architectures. A simulation is also conducted to evaluate the performance of the architecture. The simulation results show that the packet loss probability of this architecture is lower than general architectures.  相似文献   

7.
We propose a concept of wavelength synchronization to ensure the stability of ultra-dense channels in an ultra-dense wavelength division multiplexing passive optical network(UDWDM-PON)transmitter.A mode-locked laser is used to provide wavelength references for users.By injection locking the semiconductor laser,the separation of the wavelength reference is realized in an optical line terminal.The downlink and uplink wavelength references are interlaced and distributed to facilitate the synchronization of uplink carriers.In the optical network unit,the uplink optical carriers are filtered by injection locking semiconductor lasers,which achieve wavelength synchronization for the uplink users.In this Letter,an adaptive wavelength synchronization transmitter for UDWDM-PON is realized with a channel spacing of 5 GHz.  相似文献   

8.
The performance of an optical switching network is mainly determined by its core node structure. An improved optical packet switching (OPS) node structure based on recirculation optical fiber delay line (FDL) and feedback tunable wavelength converter (TWC), and a specific scheduling algorithm for the node structure are presented. This switching structure supports both point-to-point and point-to-multi- points broadcasting transmission with superior capacity expansion performance. Its superiority in packet loss probability is proved by simulation.  相似文献   

9.
A new integrated scheme based on resource-reservation and adaptive network flow routing to alleviate contention in optical burst switching networks is proposed. The objective of the proposed scheme is to reduce the overall burst loss in the network and at the same time to avoid the packet out-of-sequence arrival problem. Simulations are carried out to assess the feasibility of the proposed scheme. Its performance is compared with that of contention resolution schemes based on conventional routing. Through extensive simulations, it is shown that the proposed scheme not only provides significantly better burst loss performance than the basic equal proportion and hop-length based traffic routing algorithms, but also is void of any packet re-orderings.  相似文献   

10.
A novel optical burst switching (OBS) high speed network architecture has been proposed. To verify its feasibility and evaluate its performance, just-enough-time (JET) signaling has been considered as a high performance protocol. In the proposed architecture, to avoid burst losses, firstly, a short-prior- confirmation-packet (SPCP) is sent over the control channel that simulates the events that the actual packet will experience. Once SPCP detects a drop at any of the intermediate nodes, the actual packet is not sent but the process repeats. In order to increase network utilization, cost effectiveness and to overcome some limitations of conventional OBS, inherent codes (e.g., orthogonal optical codes (OOC)), which are codified only in intensity, has been used. Through simulations, it shows that a decrease in burst loss probability, cost effectiveness and a gain in processing time are obtained when optical label processing is used as compared with electronic processing.  相似文献   

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