Novel flat datacenter network architecture based on scalable and flow-controlled optical switch system

We propose and demonstrate an optical flat datacenter network based on scalable optical switch system with optical flow control. 4×4 dynamic switch operation at 40 Gb/s reported 300ns minimum end-to-end latency (including 25m transmission link) an

Scalable optical packet switch architecture for low latency and high load computer communication networks

High performance computer and data-centers require PetaFlop/s processing speed and Petabyte storage capacity with thousands of low-latency short link interconnections between computers nodes. Switch matrices that operate transparently in the optical domain are a potential way to efficiently interconnect 1000's of inputs/outputs, complying the end-to-end latency (~1 µs) of these systems. Current rearrangeable non-blocking switches architectures (Benes, Omega, etc..) have a reconfiguration time (expressed in clock-cycles) at most of Mog2(N), N is the number of nodes. Assuming a clock cycle of 1 ns, it follows that the latency requirement cannot be met for N >; 100. Moreover, being the switch disable during this time, the packets are either lost or buffered, limiting the maximum load of the system. In this work we present a new strictly non-blocking switch architecture with a contention resolution sub system. Key point is that the new architecture supports highly distributed control that allows for reduction of the switching time to few nanoseconds regardless the N input/output nodes. Thus, the architecture can meet the latency requirement without limiting the load of the system

Low latency and efficient optical flow control for intra data center networks

We demonstrate a highly spectral efficient optical bidirectional system based on reusing the label wavelength to implement an optical flow control for intra-data center networks. Experimental results show error free operation and an effective reduction of the system complexity

Novel flat datacenter network architecture based on scalable and flow-controlled optical switch system

We propose and demonstrate an optical flat datacenter network based on scalable optical switch system with optical flow control. Modular structure with distributed control results in port-count independent optical switch reconfiguration time. RF tone in-band labeling technique allowing parallel processing of the label bits ensures the low latency operation regardless of the switch port-count. Hardware flow control is conducted at optical level by re-using the label wavelength without occupying extra bandwidth, space, and network resources which further improves the performance of latency within a simple structure. Dynamic switching including multicasting operation is validated for a 4x4 system. Error free operation of 40 Gb/s data packets has been achieved with only 1 dB penalty. The system could handle an input load up to 0.5 providing a packet loss lower that 10-5 and an average latency less that 500ns when a buffer size of 16 packets is employed. Investigation on scalability also indicates that the proposed system could potentially scale up to large port count with limited power penalty

Experimental assessment of a scalable and flow-controlled optical switch system for flat datacenter networks

We propose and demonstrate an optical flat data center network based on scalable optical switch system with optical flow control. Experimental evaluation of the system at data rate of 40 Gb/s includes a 4×4 optical switch with highly distributed control for port-count independent nanosecond reconfiguration time for low latency operation. The hardware flow control at the optical level allows fast retransmission control of the electrical buffered packets at the edge nodes preventing the need of optical buffers. Moreover, this makes a dedicated flow control network redundant, which effectively reduces system complexity and power consumption. Dynamic switch operation reported 300 ns minimum end-to-end latency (including 25 m transmission link) an

Mode-Locking by Nonlinear Polarization Rotation in a Semiconductor Optical Amplifier

We numerically investigate a passive mode-locking system based on nonlinear polarization rotation in a semiconductor optical amplifier (SOA), which has been experimentally demonstrated [1].The principle of polarization-dependent gain saturation induced by the high-intensity part of the optical pulse in a SOA makes it possible to reshape the pulse in such a way that the low-intensity part is cut away. This will result in pulse narrowing and, when realized in a loop with sufficiently high gain, will lead to mode locking. The reshaping is realized by simple polarization controlling elements. Extensive numerical simulations have been done for commercially available SOA with a consistent pulse propagation model based on [2]. Our results show that the linewidth enhancement factor α plays a crucial role in the pulse built-up process. With fixed current, α should be larger than a critical value to obtain net roundtrip gain. Meanwhile, with a fixed α, there is a minimum current for the system to build up. On the other hand, if the current is increased beyond some critical value, instabilities instead of mode locking occur. The system normally takes several tens of roundtrips to build up to a stable state. In Fig.1, one typical built-up process from a super Gaussian pulse with white noise is shown. In the unrealistic case of dispersion-free operation, there is no fundamental limit to the pulse narrowing; finally nothing is left in the cavity after several hundred of roundtrips. However, in practice, the pulse width in stable state is determined by cavity dispersion and ultra-fast gain dynamics, where the latter is current dependent. The pulse root mean squared widt