Current Issue : January - March Volume : 2020 Issue Number : 1 Articles : 5 Articles
In this paper, we experimentally present a novel, all-optical spectral efficient vertical-cavity surface-emitting laser- (VCSEL-)\nbased technique for routing and spectrum assignment in optical networks. Exploiting all optical VCSEL-to-VCSEL injection to\nattain cross gain modulation, the optical transmitter is optimized for optical transmission paths to assure quality of service by\novercoming blockage for differentiated bandwidth demands during network congestion incidences. A 10 Gbps directly modulated\n1549 nm master VCSEL is optically injected into the 1549nm side modes of a 1550nm slave VCSEL. The Shannon limit is\nconsidered for higher transmission rates with the problem decomposed into degraded routing and spectrum assignment and\nchromatic dispersion in the optical transmission link penalties. In this work, the proposed technique achieved a 1.3 dB penalty for\ntransmission over a 25km G.655 nonzero dispersion-shifted single-mode optical fibre, a value within the transmission media and\noptical system characteristics of 3 dB as recommended by the International Telecommunication Union-Telecommunication (ITU-T).\nThe number of transceivers, switches, and optical transmission links in the network was reduced, increasing the number of satisfied\nbandwidth requests, thus optimizing the spectral resource utilization....
Telemetry allows to monitor the behavior of a system and it is applied to many different and\npopular fields such as motorsport. In this case, a data-logger collects all the data coming from different\nautomobile sensors providing a very reliable image of the car status and a better vehicle setup. This\npaper is focused on the development of a new data-logging system for motorsport application, which\nmeets several process constraints, such as high throughput and low power consumption that, to the\nbest of the authorsâ?? knowledge, the available devices on the market were not able to satisfy. The new\ndata-logger consists of a fixed and a removable part, which exchanges data through a transceiver\nexploiting the visible light communication (VLC) technology. In this way, every physical contact\nbetween the two parts of the system is avoided. All the communication procedures are managed by a\nmicro-controller mounted on each part of the system. The transceiver consists of the AFBR-1634Z and\nAFBR-2634Z (Broadcom Limited, San Jose, CA, USA) components, the optical fiber transmitter and\nthe receiver, respectively, produced by Broadcom Inc. By keeping the distance short between them,\nthey can assure a real wireless communication, even without using a high throughput technology\nlike optical fiber. The entire system is powered by an inductive coupling system. In order to test\nthe transceiver, it is connected to a micro-controller reaching a data rate of 8 Mbit/s. But even better\nperformance is achieved by upgrading the micro-controller and changing the transmission technique,\nconnecting the transceiver to the serial peripheral interface (SPI) port of the micro-controller: in this\ncase, a data rate of 21 Mbit/s is reached, perfectly suitable with the application requirements and\neven further....
Due to the large size of space targets, migration through resolution cells (MTRC) are\ninduced by a rotational motion in high-resolution bistatic inverse synthetic aperture radar (Bi-ISAR)\nsystems. The inaccurate correction of MTRC degrades the quality of Bi-ISAR images. However, it is\nchallenging to correct the MTRC where sparse aperture data exists for Bi-ISAR systems. A joint\napproach of MTRC correction and sparse high-resolution imaging for Bi-ISAR systems is presented in\nthis paper. First, a Bi-ISAR imaging sparse model-related to MTRC is established based on compress\nsensing (CS). Second, the target image elements and noise are modeled as the complex Laplace prior,\nand the Gaussian prior, respectively. Finally, the high-resolution, well-focused image is obtained by\nthe full Bayesian inference method, without manual adjustments of unknown parameters. Simulated\nresults verify the effectiveness and robustness of the proposed algorithm....
Tuning nonlinearity of the laser is the main source of deterioration of the spatial resolution \nin optical frequency -domain reflectometry (OFDR) system. In this paper, we develop methods for \ntuning nonlinearity correction in an OFDR system from the aspect of data acquisition and post -\nprocessing. An external clock based on a zero -crossing detection is researched and implemented \nusing a customized circuit. Equal -spacing frequency sampling is, therefore, achieved in real -time. \nThe zero -crossing detection for the beating frequency of 20 MHz is achieved. The maximum sensing \ndistance can reach the same length of the auxiliary interferometer. Moreover, a nonlinearity \ncorrection method based on the self -reference method is proposed. The auxiliary interferometer is \nno longer necessary in this scheme. The tuning information of the laser is extracted by a strong \nreflectivity point at the end of the measured fiber. The tuning information is then used to resample \nthe raw signal, and the nonlinearity correction can be achieved. The spatial resolution test and the \ndistributed strain measurement test were both performed based on this nonlinearity correction \nmethod. The results validated the feasibility of the proposed method. This method reduces the \nhardware and data burden for the system and has potential value for system integration and \nminiaturization....
Nitrogen-vacancy color centers in diamond are a very promising medium for many\nsensing applications such as magnetometry and thermometry. In this work, we study nanodiamonds\ndeposited from a suspension onto glass substrates. Fluorescence and optically detected magnetic\nresonance spectra recorded with the dried-out nanodiamond ensembles are presented and a suitable\nscheme for tracking the magnetic-field value using a continuous poly-crystalline spectrum is\nintroduced. Lastly, we demonstrate a remote-sensing capability of the high-numerical-aperture\nimaging fiber bundle with nanodiamonds deposited on its end facet....
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