Temat: optical communication

Skocz do pozycji: 1.

Tytuł:: All-optical intensity noise suppression for solid-state and semiconductor lasers
Autorzy:: Csörnyei, M.
Berceli, T.
Marozsák, T.
Tematy:: laser noise
neodymium:solid lasers
optical communication; Pokaż więcej
Wydawca:: Instytut Łączności - Państwowy Instytut Badawczy
Powiązania:: https://bibliotekanauki.pl/articles/309387.pdf Link otwiera się w nowym oknie
Opis:: This paper will report on a new all-optical technique of relative intensity noise (RIN) suppression for solidstate and semiconductor lasers. The new scheme we have used is based on an unbalanced Mach-Zehnder interferometer (UMZI), which is able to cancel the intensity noise enhancement at relaxation resonance. Although the relaxation oscillations frequency and the level of the corresponding noise maximum are extremely different concerning solid-state microchip lasers and semiconductor laser diodes, the proposed passive noise suppression is well suited for both types of laser sources used in telecommunication. The UMZ fiber interferometer solution for solid-state lasers demonstrated hereunder was generalized and deployed in case of semiconductor lasers as well.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 2.

Tytuł:: Control of optical chaos spectrum in semiconductor laser for secure RoF communication
Autorzy:: Mazhar, Danish Ali
Ali, Syed Zafar
Islam, Muhammad Khawar
Tematy:: chaos
radio over fiber
secure optical communication; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/2172849.pdf Link otwiera się w nowym oknie
Opis:: A critical requirement in optical chaos based secure radio over fiber (RoF) system design is the ability to control center frequency, spectral bandwidth, power level and signature of chaos to submerge message with sufficient horizontal and vertical margins both in time and frequency domains. Once frequency domain masking is completely achieved, time domain masking is met automatically, the former being more stringent. In a direct modulated semiconductor laser, the three control parameters are bias current (Ibias), modulation current (Imod) and modulation frequency (ωa). It is found that Imod increases bandwidth and amplitude dynamic range of chaotic pulses. Ibias increases the cavity power and hence average peak amplitude of laser chaotic pulses. The modulation frequency increases the speed of overall cavity dynamics and hence is used to increase the bandwidth of chaos but a corresponding increase in bias and modulation currents is required to support high repetition pulses. The results show relationship between three control parameters (bias current, modulation current and modulation frequency) in a direct modulated semiconductor laser and optical chaos bandwidth using regression.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 3.

Tytuł:: Opportunities for the out of the 1550 nm Window transmission
Możliwości wykorzystania transmisji poza pasmem 1550 nm
Autorzy:: Turkiewicz, Jarosław Piotr
Tematy:: optical communication
optical fibre
optical amplifier
komunikacja optyczna
światłowód
wzmacniacz optyczny; Pokaż więcej
Wydawca:: Politechnika Lubelska. Wydawnictwo Politechniki Lubelskiej
Powiązania:: https://bibliotekanauki.pl/articles/408278.pdf Link otwiera się w nowym oknie
Opis:: In this paper, opportunities for transmission in the 850 nm and 1310 nm windows are reviewed. In particular, the mentioned windows can be utilized for the data centre related transmission.
W artykule dokonano analizy możliwości wykorzystania okien transmisyjnych 850 nm i 1310 nm. Rozważane okna można wykorzystać do realizacji transmisji dla potrzeb centrów danych.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 4.

Tytuł:: The Threat of Optical Transmission Jamming
Autorzy:: Kowalczyk, Marcin
Marzecki, Michał
Siuzdak, Jerzy
Tematy:: clip-on coupler
optical communication jamming
optical networks vulnerability; Pokaż więcej
Wydawca:: Instytut Łączności - Państwowy Instytut Badawczy
Powiązania:: https://bibliotekanauki.pl/articles/27312945.pdf Link otwiera się w nowym oknie
Opis:: In this paper, we investigate how data transmissions may be affected by various types of optical interference introduced into the fiber on purpose, via a clip-on coupler. The research proved that transmissions may be jammed completely using inexpensive equipment readily available on the market, provided that the attacker has physical access to the fiber optic cable. The most dangerous attacks rely on a typical, slowly modulated communication laser with a rectangular waveform. This study urges further research aimed at counteracting such attacks.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 5.

Tytuł:: Nonlinear optics of the thin-film quasiwaveguide amplifier: applications to directional switching in the optical communication systems
Autorzy:: Djotyan, G.P.
Arutunyan, V.M.
Bakos, J.S.
Sörlei, Z.
Tematy:: thin-film laser
directoral switching
four-wave mixing
optical communication systems; Pokaż więcej
Wydawca:: Instytut Łączności - Państwowy Instytut Badawczy
Powiązania:: https://bibliotekanauki.pl/articles/308725.pdf Link otwiera się w nowym oknie
Opis:: We examine nonlinear optical effects in the active medium of the thin-film quasiwaveguide amplifier-oscillator with injection of the external signal. The injection locking has been obtained in the case when both the frequency and the direction of propagation of the injected signal differ from those for a free-running thin-film laser which offers a possibility for the frequency and directional switching of the output of the thin-film laser. The effects of four wave mixing and phase conjugation have been discussed in the active medium of the thin-film laser when additional mirrors forming an external resonator have been used.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 6.

Tytuł:: Performance analysis of terrestrial WDM-FSO Link under Different Weather Channel
Autorzy:: Mazin, Ali A. Ali
Tematy:: WDM
FSO
optical communication
non return to zero
weather attenuation; Pokaż więcej
Wydawca:: Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Powiązania:: https://bibliotekanauki.pl/articles/1188080.pdf Link otwiera się w nowym oknie
Opis:: In this paper, the performance of WDM-FSO communications system is simulation analyzed, using NRZ modulation technique over different weather conditions. Based on this technique the received signal power, signal to noise ratio, Q. factor, and BER are analyzed. The characteristics of WDM was studied for free space optical communication. Simulation results indicate that the performance of WDM-FSO are more suited for strong attenuation. On the other hand, the suitability of distance link under this technique are studied, where WDM has more advantage when used in optical communication system.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 7.

Tytuł:: Indoor localization based on visible light communication and machine learning algorithms
Autorzy:: Ghonim, Alzahraa M.
Salama, Wessam M.
Khalaf, Ashraf A. M.
Shalaby, Hossam M. H.
Tematy:: free-space optical communication
visible light communication
neural networks
random forests
machine learning; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Powiązania:: https://bibliotekanauki.pl/articles/2063908.pdf Link otwiera się w nowym oknie
Opis:: An indoor localization system is proposed based on visible light communications, received signal strength, and machine learning algorithms. To acquire an accurate localization system, first, a dataset is collected. The dataset is then used with various machine learning algorithms for training purpose. Several evaluation metrics are used to estimate the robustness of the proposed system. Specifically, authors’ evaluation parameters are based on training time, testing time, classification accuracy, area under curve, F1-score, precision, recall, logloss, and specificity. It turned out that the proposed system is featured with high accuracy. The authors are able to achieve 99.5% for area under curve, 99.4% for classification accuracy, precision, F1, and recall. The logloss and precision are 4% and 99.7%, respectively. Moreover, root mean square error is used as an additional performance evaluation averaged to 0.136 cm.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 8.

Tytuł:: Photonics and Web Engineering 2011
Autorzy:: Romaniuk, R. S.
Tematy:: nanomaterials
optical fibers
optoelectronics
photonics
measurement systems
optical communication systems
photonic sources and detectors; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/226302.pdf Link otwiera się w nowym oknie
Opis:: The paper presents a digest of chosen technical work results shown by young researchers from different technical universities in this country during the SPIE-IEEE Wilga 2011 symposium on Photonics and Web Engineering. Topical tracks of the symposium embraced, among others, nanomaterials and nanotechnologies for photonics and telecom, sensory and nonlinear optical fibers, object oriented design of hardware, photonic metrology, optoelectronics and photonics applications, photonics-electronics co-design, optoelectronic and electronic systems for telecom, astronomy and high energy physics experiments, JET and pi-of-the sky experiments development. The symposium is an annual summary in the development of numerable Ph.D. theses carried out in this country in the area of advanced electronic and photonic systems. It is also an occasion for young researchers to meet together in a large group (under the patronage of IEEE) spanning the whole country with guests from this part of Europe. A digest of Wilga references is presented [1-92].
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 9.

Tytuł:: Average capacity analysis of FSO system with Airy beam as carrier over exponentiated Weibull channels
Autorzy:: Li, Yi
Chu, Xingchun
Han, Zhongxiang
Tang, Hanling
Song, Xinkang
Tematy:: Airy beam
free-space optical communication
channel capacity
exponentiated Weibull model; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/2202763.pdf Link otwiera się w nowym oknie
Opis:: Based on scintillation index of Airy beam and exponentiated Weibull channel model, analytical expressions of average channel capacity for free-space optical (FSO) communication links with Airy beam as signal carrier under weak atmospheric turbulence and on-off keying modulation scheme are derived. The average capacity at various propagation distances, transverse scale factors and exponential decay factors has been evaluated. And we compared the average capacity of FSO links with Airy beam and Gaussian beam as signal carrier. The results show that the average capacity of FSO links with Airy beam as carrier increases with the increase of mean signal-to-noise ratio and decreases uniformly with the increase of propagation distance. When the transverse scale factor of Airy beam is about 2 cm, a higher average capacity can be obtained. And the smaller the exponential decay factor of Airy beam, the larger the average capacity. Under the same source power or source width, the average capacity of FSO links with Airy beam as carrier is significantly higher than that of FSO links with Gaussian beam as carrier. The results of this research have some reference significance for the application of Airy beam in FSO communication system.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 10.

Tytuł:: The improvement of fiber-detection method to enhance the output of amplify-received relaying on FSO communications
Autorzy:: Darusalam, Ucuk
Priambodo, Purnomo Sidi
Zulkifli, Fitri Yuli
Rahardjo, Eko Tjipto
Tematy:: amplify-received relaying
optical relaying network
free-space optical communication
noise suppression
optical spatial filter
scintillation; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czasopisma i Monografie PAN
Powiązania:: https://bibliotekanauki.pl/articles/27311966.pdf Link otwiera się w nowym oknie
Opis:: The performance of free-space optical (FSO) communications that using an optical amplifier (OA) in the scheme of an amplify-received (AR)-relaying has a major drawback in the detection of input signal quality under the effects of turbulence. As an OA is based on a fiber-detection (FD) method to receive and delivers a signal at the amplification process stage, there is an opportunity to implement an optical spatial filter (OSF) to improve the quality of an input signal. In this paper, as the continuation of previous work on the direct-detection, the OSF is applied on the AR-relaying. The novelty proposed in this work is the improvement of FD method where the OSF is designed as the integration of cone reflector, pinhole and multi-mode fiber with an OA. The OSF produces an optical signal, the input of the OA, which minimizes the effects of turbulence, background noise and signal fluctuation. Thus, OA in AR-relaying produces signal output with high power and rise up below threshold level. Additionally, an OSF with a lower pinhole diameter produces the best quality of the signal spectral to be delivered into an EDFA. Through this implementation, the performance of optical relaying on FSO can be significantly improved.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Informacja

Wyszukujesz frazę "optical communication" wg kryterium: Temat