Ashenafi Kiros Medhin

Experimental Demonstration of Multidimensional Switching Nodes for All-Optical Data Center Networks

This paper reports on a novel ring-based data center architecture composed of multidimensional switching nodes. The nodes are interconnected with multicore fibers and can provide switching in three different physical, hierarchically overlaid dimensions (space, wavelength, and time). The proposed architecture allows for scaling in different dimensions while at the same time providing support for connections with different granularity. The ring topology reduces the number of different physical links required, leading to simplified cabling and easier link management, while optical bypass holds the prospect of low latency and low-power consumption. The performance of the multidimensional switching nodes has been investigated in an experimental demonstration comprising three network nodes connected with multicore fibers. Both high capacity wavelength connections and time-shared subwavelength connections have been established for connecting different nodes by switching indifferent physical dimensions. Error-free performance (BER <; 10-9) has been achieved for all the connections with various granularity in all the investigated switching scenarios. The scalability of the system has been studied by increasing the transmission capacity to 1 Tbit/s/core equivalent to 7 Tbit/s total throughput in a single seven-core multicore fiber. The error-free performance (BER <; 10-9) for all the connections confirms that the proposed architecture can meet the existing

Experimental demonstration of multidimensional switching nodes for all-optical data centre networks

We experimentally demonstrate network nodes that enable SDM/WDM/TDM switching. 1 Tbit/s/core error-free performance is achieved for connections with different granularities being switched between three network nodes interconnected with 7-core multicore fibres.

Scalable In-Band Optical Notch-Filter Labeling for Ultrahigh Bit Rate Optical Packet Switching

We propose a scalable in-band optical notch-filter labeling scheme for optical packet switching of high-bit-rate data packets. A detailed characterization of the notch-filter labeling scheme and its effect on the quality of the data packet is carried out in simulation and verified by experimental demonstrations. The scheme is able to generate more than 91 different labels that can be applied to 640-Gb/s optical time division multiplexed packets causing an eye opening penalty of <;1.2-dB. Experimental demonstration shows that up to 256 packets can be uniquely labeled by employing up to eight notch filters with only 0.9-dB power penalty to achieve BER of 1E-9. Using the proposed labeling scheme, optical packet switching of 640 Gb/s data packets is experimentally demonstrated in which two data packets are labeled by making none and one spectral hole using a notch filter and are switched using a LiNbO3 switch. The performance of the two data packets before/after switching is investigated by BER measurements and all 256 data channels achieve BER 1E-9 at the expense of only 4.1-dB total system penalty.

Increase in data capacity utilising dimensions of wavelength, space, time, polarisation and multilevel modulation using a single laser

Increasing the capacity of optical networks while have the objective of lowering the total consumed energy per bit is challenging. By exploiting several dimensions, i.e. wavelength, space, time, polarisation and multilevel modulation simultaneously, a single laser can offer formidable capacity performance with potentially reduced energy consumption per bit. Up to 43 Tbit/s has been demonstrated.

Experimental demonstration of optical switching of Tbit/s data packets for high capacity short-range networks

Record-high 1.28-Tbit/s optical data packets are experimentally switched in the optical domain using a LiNbO3 switch. An in-band notch-filter labeling scheme scalable to 65,536 labels is employed and a 3-km transmission distance is demonstrated.

1×4 Optical packet switching of variable length 640 Gbit/s data packets using in-band optical notch-filter labeling

We experimentally perform 1×4 optical packet switching of variable length 640 Gbit/s OTDM data packets using in-band notch-filter labeling with only 2.7-dB penalty. Up to 8 notches are employed to demonstrate scalability of the labeling scheme to 1×256 switching operation.