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1
Content available Analysis of Free-Space Optics Development
Mikołajczyk J., Bielecki Z., Bugajski M., Piotrowski J., Wojtas J., Gawron W., Szabra D., Prokopiuk A.
Metrology and Measurement Systems
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2017
|
Vol. 24, nr 4
653--674
EN
The article presents state of work in technology of free-space optical communications (Free Space Optics - FSO). Both commercially available optical data links and their further development are described. The main elements and operation limiting factors of FSO systems have been identified. Additionally, analyses of FSO/RF hybrid systems application are included. The main aspects of LasBITer project related to such hybrid technology for security and defence applications are presented.
2
Content available remote Data encryption of optical fibre communication using pseudo-random spatial light modulation
Kowalski M., Życzkowski M.
Opto-Electronics Review
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2016
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Vol. 24, No. 2
75--81
EN
We propose and study a new technique for securing fibre data communication. The paper presents a method for optical encryption of information transmitted with a traditional fibre link. The encryption method uses a spatial light modulator which converts light pulses representing original data into pseudo-random patterns. A linear combination of light pulses with pseudo-random patterns provides a required encryption performance. The main element of the encryptor is the spatial light modulator which comprises a matrix of cells selectively transmitting or blocking the light beam depending on the pseudo-random configuration of cells. The encrypted information is transmitted through the optical fibre. The decryption process relies on a computational solving of linear program or greedy pursuit. We present a brief description of the method, theoretical analysis and results of numerical simulation. A physical model concept of the method is also presented.
3
Content available Analog-based duobinary-4-PAM for electrical bandwidth limited optical fiber links
Suhr L.F., Madsen P., Monroy I. T., Olmos J. J. V.
Optica Applicata
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2016
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Vol. 46, nr 1
71--78
EN
This paper presents a demonstration of a seven level duobinary-4-PAM signal operating at 10.16 Gbit/s. The polybinary generation is achieved by a simple electrical Bessel filter of 5th order, with a frequency cut-off of 1.8 GHz. We assess the impact of the filter placement, either at the transmitter or the receiver, and find the impact is minimal in terms of bit error rate performance in transmissions of up to 40 km of single mode fiber.
4
Wykorzystanie głębokiego nasycenia wzmacniacza SOA i efektu uśredniania mocy sygnału wejściowego do przeciwdziałania przesłuchowi międzykanałowemu i stratom mocy przy pracy SOA w systemie DWDM
Dyc F. M., Turkiewicz J. P.
Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne
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2013
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nr 8-9
639-644
PL
Przedstawiono nowe podejście do przeciwdziałania przesłuchowi międzykanałowemu i stratom mocy wprowadzanym przez wzmacniacz SOA. Zakłada ono wykorzystanie głębokiej saturacji SOA oraz efektu uśredniania sygnału wejściowego. Wykazano, że efekt uśredniania ma najsilniejszy pozytywny wpływ na ograniczenie zniekształceń wprowadzanych przez SOA, kiedy wzmacniacz pracuje w głębokiej saturacji z wieloma kanałami Badano wpływ liczby kanałów, przepływności, mocy i współczynnika ekstynkcji na poziom zniekształceń.
EN
A novel countermeasure the interchannel crosstalk and resulting power penalty. The proposed method is based on the utilization of the SOA in the deep saturation and averaging of the input signal The averaging effect has the strongest positive effect in the SOA deep saturation for a high channel number. The influence of the channel number, bit rate and the signal extinction ratio on the signal distortions.
5
Content available remote Optical soliton perturbation with log law nonlinearity
Girgis L., Milovic D., Hayat T., Aldossary O. M., Biswas A.
Optica Applicata
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2012
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Vol. 42, nr 3
447-454
EN
This paper studies the perturbation theory of optical solitons with log law nonlinearity. The adiabatic dynamics of the Gausson parameters are determined in the presence of the perturbation terms. The fixed point is also found and finally the numerical simulation is carried out.
6
Content available remote Analysis of crosstalk in mixed 40 Gb/s and 100 Gb/s DWDM system with alien wavelength
Perlicki K, Okrasa W
Optica Applicata
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2012
|
Vol. 42, nr 4
829--834
EN
The modern dense wavelength division multiplexing (DWDM) management system has no a priori knowledge of alien wavelength parameters. The result of this is unforeseeable impact of alien wavelength parameters on friendly wavelengths quality. The numerical results of the impact of alien wavelength on optical transmission quality are presented, and experimental demonstration based on Alcatel–Lucent 1830 Photonic Service Switch PSS 32 transmission system is shown. The obtained results indicate that alien wavelength bandwidth must be restricted.
7
Content available remote Multichannel comb filter based on linearly chirped fiber Bragg grating and DC phase shift
Sun G., Wang R., Pu Tao, Wang Hongbo, Wei Zhihu
Optica Applicata
|
2011
|
Vol. 41, nr 4
791--797
EN
A novel approach to implement high channel-count comb filters based on a DC phase shift is proposed. Various channel spacings can be achieved by a single chirped phase mask and a submicrometer-precision translation stage. Simulation and experiment show that arbitrary phase shifts introduced by DC refractive index modulation can be achieved. An multichannel comb filter with channel spacing of 100 GHz, 50 GHz and 40 GHz is implemented with the same phase mask. A comparison between the proposed DC phase shift and traditional discrete phase shift is made.
8
Content available remote Optical solitons with bandwidth limited amplification in non-Kerr law media
Biswas A., Wheeler D.
Optica Applicata
|
2010
|
Vol. 40, nr 4
801--809
EN
This paper studies optical solitons with linear attenuation and bandpass filters. The Kerr and power laws of nonlinearity are considered. The governing equations are integrated by the aid of He's semi-inverse variational principle. The parameter domains are identified.
9
Content available remote Cost-effective method for generating >20 GHz pulse trains using actively mode locking fiber ring laser
Kim Sun-Jong, Park Chang-Soo
Optica Applicata
|
2004
|
Vol. 34, nr 1
17-24
EN
This study proposes a simple method to generate high-speed pulse of more than 20 GHz. Its cost performance ratio in an actively rational harmonic mode locking scheme is maximized when the multiplication factor p = 4 and 6. The operation is based on a relatively simple structure using the optical Mach–Zehnder modulator (MZM) biased at the minimum transmission peak and optical filtering via a Mach–Zehnder interferometer (MZI) comb filter. Stable and amplitude-equalized pulse trains with a repetition rate of ~20.345 GHz are successfully demonstrated.
10
Content available remote Raman gain characterization in standard single mode optical fibres for optical simulation purposes
Andre P. S., Correia R., Borghesi L. M., Teixeira A. L. J., Nogueira R. N., Lima M. J. N., Kalinowski H. J., Da Rocha F., Pinto J. L.
Optica Applicata
|
2003
|
Vol. 33, nr 4
559-573
EN
We report on the measurement of the Raman gain coefficient in a standard single mode optical fibre (SMF), based on the power transfer between a high intensity pump signal and a counter-propagated broadband probe signal technique. The results were complemented with spontaneous Raman spectroscopy. The values of 7.48×10–27 mW–1Hz–1, 0.540×10–13 mW–1, 3.03 fs, 12.40 fs, 40.78 fs and 0.160 were experimentally obtained for the Raman gain slope, maximum value of the gain coefficient, Raman time constant, first and second parameters of the Raman response function and fractional contribution of the delayed Raman response, respectively.
11
Rozwój telekomunikacji światłowodowej w kraju
Romaniuk R. S.
Elektronika : konstrukcje, technologie, zastosowania
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2002
|
Vol. 43, nr 5
6-13
PL
Światłowodowa infrastruktura telekomunikacyjna w kraju znajduje się w okresie intensywnego rozwoju. Szereg inwestorów międzynarodowych i operatorów krajowych buduje od nowa, modernizuje lub rozwija swoje sieci własnościowe lub wchodzi w umowy dzierżawne na wielką skalę, na zagregowanym w skali kraju poziomie rzędu mld USD. Mimo tego sieć jest niejednolita, z niedostatecznym pasmem, brakami gwarancji usług, z wieloma obszarami słabo obsługiwanymi, zbyt nielicznymi połączeniami międzynarodowymi i, według powszechnej opinii, zawyżonymi cenami usług dla indywidualnych abonentów zarówno prawnych, jak i fizycznych. W rozwoju infrastruktury światłowodowej widoczne są dwie wyraźne tendencje: kładzenie od nowa grubych rur optycznych - kabli zawierających nawet ponad 500 włókien (dla pasma C L oraz XL) oraz inwestycje w DWDM na głównych kierunkach ruchu telekomunikacyjnego z wykorzystaniem zastanej infrastruktury (poprzednio pracującej w paśmie 1300 nm).
EN
Optical communications infrastructures is undergoing an intense development in his country now. A number of international investors and domestic operators are building from the beginning, modernizing or developing proprietary network or leasing wide area systems on a large scale. The aggregate level of these processes is of the order of bil. $ . Despite of this the network is not homogeneous, has not satisfactory bandwidth, lacks the QoS, has inadequate international connections, and (according to prevailing opinions) the prices are too high for corporate as well as private users. The intense development of the optical infrastructure is governed by two dominant tendencies: burying new large, fat, optical pipes - cables containing even as much fibers as 500 (for C, L and XL optical bands) and investments in DWDM for main traffic directions (previously working in 1300 nm band).
12
Content available remote Impact of frequency response of two-segment semiconductor laser on dispersion supported transmission with a binary optical signal at the receiver
Perlicki K., Siuzdak J.
Opto-Electronics Review
|
2000
|
Vol. 8, No. 1
61-66
EN
Analysis of impact of frequency response of two-segment DFB laser on conversion of a frequency-modulated signal to amplitude modulation through dispersion in an optical fibre is presented. A novel modulation scheme that produces a binary optical signal at the fibre output is used. This new scheme is based on the linear frequency modulation along with the Manchester coding. A 5 Gb/s optical transmission system is presented ; it uses the new method of FM-AM conversion supported transmission. The propagation of optical field through a fibre is described by nonlinear Schrödinger equation, which is solved numerically by the split-step Fourier method.
13
Content available Recent advances in PBG structures
Vorgul I.Yu., Marciniak M.
Journal of Telecommunications and Information Technology
|
2000
|
nr 1-2
71-76
EN
We propose a review of word science achievements in the extremely extended for the recent few years field of photonic band gap structures The review concerns both theoretical and experimental investigations on PBG structures toward fabrication of the most optimal ones for different applications. The attention is given to the obtained results as well as to the used and developed methods.
14
Content available Power penalty caused by Stimulated Raman Scattering in WDM Systems
Pietrzyk S., Szczęsny W., Marciniak M.
Journal of Telecommunications and Information Technology
|
2000
|
nr 1-2
52-58
EN
In this paper we present results of an investigation into the power penalty introduced by Stimulated Raman Scattering (SRS) in WDM systems with concentration on application of dispersion-shifted single-mode optical fibres (G.653) and unequal channel allocation schemes. System parameters based on ITU-T Recommendation G.692 and analytic formulas were used in calculations. It is shown that SRS does present a practical limitation to the multichannel systems. We also indicate limitations of the G.692 Recommendation and we point at directions of study in the area of nonlinear phenomena and multichannel systems.
15
Content available Impact of nonlinear optical phenomena on dense wavelength division multiplexed transmission in fibre telecommunication systems
Szczęsny W., Marciniak M.
Journal of Telecommunications and Information Technology
|
2000
|
nr 1-2
61-65
EN
In the paper results of analysis of nonlinear phenomena in optical fibres: Self-Phase Modulation, Cross-Phase Modulation, Four-Wave Mixing and Stimulated Raman Scattering and their influence on Dense-Wavelength Division Multiplexed system performance are reported. Different nonuniform optical channel allocation schemes based on ITU Recommendation G.692 100 GHz frequency grid are compared with uniform channel distribution. The level of nonlinear cross-talk is determined for different levels of the total optical power. As an example a 10 Gbit/s D-WDM dispersion-shifted single mode fibre link with dispersion-compensating fibres is envisaged. The directions for optimization of the system design in view of actual international standardization trends are pointed out.
16
Transmisja optyczna wspomagana dyspersją światłowodu
Perlicki K.
Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne
|
1999
|
nr 12
832-835
PL
Omówiono zjawisko konwersji modulacji częstotliwości na modulację amplitudy powodowanej przez dyspersję
EN
Conversion of a frequency modulated signal to amplitude modulation through dispersion in an optical fibe
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