Holographic mode-selective launch for bandwidth enhancement in multimode fiber

With rapidly growing bandwidth demands in Local Area Networks, it is imperative to support next generation speeds beyond 40Gbit/s.Various holographic optimization techniques using spatial light modulators have recently been explored for adaptive channel impulse response improvement of MMF links. Most of these experiments are algorithmic-oriented. In this paper, a set of lenses and a spatial light modulator, acting as a binary amplitude filter, played the pivotal role in generating the input modal electric field into a graded-index MMF, rather than algorithms. By using a priori theoretical information to generate the incident modal electric field at the MMF, the bandwidth was increased by up to 3.4 times

Multidiameter optical ring and Hermite–Gaussian vortices for wavelength division multiplexing–mode division multiplexing

Optical vortices are high-capacity data carriers for mode division multiplexing (MDM) in multimode fiber (MMF). This paper reports on the MDM of a combination of helical-phased optical vortices comprising donut modes and Hermite–Gaussian (HG) modes for different radial offsets from the MMF axis. A data rate of 44 Gbps is achieved for wavelength division multiplexing–MDM of two pairs of helical-phased donut mode and HG mode at wavelengths 1550.12 and 1551.72 nm for a MMF length of 1500 m

Mining top-k regular episodes from sensor streams

International audienceThe monitoring of human activities plays an important role in health-care applications and for the data mining community. Existing approaches work on activities recognition occurring in sensor data streams. However, regular behaviors have not been studied. Thus, we here introduce a new approach to discover top-k most regular episodes from sensors streams, TKRES. The top-k approach allows us to control the size of the output, thus preventing overwhelming result analysis for the supervisor. TKRES is based on the use of a simple top-k list and a k-tree structure for maintaining the top-k episodes and their occurrence information. We also investigate and report the performances of TKRES on two real-life smart home datasets

An optical synchronous up counter based on electro-optic effect of lithium niobate based Mach–Zehnder interferometers

Sequential circuits have the ability to store, retain and then retrieve information when needed at a later time. They act as storage elements and have memory. However, due to ever increasing demand of data rate, already existing electronic signal processing devices have become obsolete due to their large latency. To overcome the existing bottleneck, a 4-bit synchronous up counter using electro-optic effect of Mach–Zehnder interferometer has been proposed. The study is carried out by simulating the proposed device with beam propagation method

Binary spatial amplitude modulation of continuous transverse modal electric field using a single lens for mode selectivity in multimode fiber

The demand for portable real-time optical applications such as medical optical sensors and optical transceivers instigate the need for compact optical designs.The aim of this paper is to demonstrate a new, compact design for binary spatial amplitude modulation in a multimode fiber-based optical transceiver, adapted from microscopy.The continuous-amplitude transverse modal electric field of an infinite parabolic multimode fiber is retrieved from a binary amplitude-modulated field using a single lens.The retrieved field is in good agreement with the original modal electric field

Multimedia Traffic Routing in Multilayer WDM Networks

The advent of real-time multimedia services over the Internet has stimulated new technologies for expanding the information carrying capacity of optical network backbones. Multilayer wavelength division multiplexing (WDM) packet switching is an emerging technology for increasing the bandwidth of optical networks. Two algorithms for the routing of the multimedia traffic flows were applied: (i) Capacitated Shortest Path First (CSPF) routing, which minimizes the distance of each flow linking the given source and destination nodes and satisfying capacity constraints; and (ii) Flow Deviation Algorithm (FDA) routing, which minimizes the network-wide average packet delay.Comment: 10 pages, 8 figure

Mining High Utility Itemsets with Regular Occurrence

High utility itemset mining (HUIM) plays an important role in the data mining community and in a wide range of applications. For example, in retail business it is used for finding sets of sold products that give high profit, low cost, etc. These itemsets can help improve marketing strategies, make promotions/ advertisements, etc. However, since HUIM only considers utility values of items/itemsets, it may not be sufficient to observe product-buying behavior of customers such as information related to "regular purchases of sets of products having a high profit margin". To address this issue, the occurrence behavior of itemsets (in the term of regularity) simultaneously with their utility values was investigated. Then, the problem of mining high utility itemsets with regular occurrence (MHUIR) to find sets of co-occurrence items with high utility values and regular occurrence in a database was considered. An efficient single-pass algorithm, called MHUIRA, was introduced. A new modified utility-list structure, called NUL, was designed to efficiently maintain utility values and occurrence information and to increase the efficiency of computing the utility of itemsets. Experimental studies on real and synthetic datasets and complexity analyses are provided to show the efficiency of MHUIRA combined with NUL in terms of time and space usage for mining interesting itemsets based on regularity and utility constraints