Wyniki wyszukiwania - Biblioteka Nauki

1

Multiple fiber Bragg grating sensing system based on active mode-locking fiber laser

100%

Meng D. , Yu X. , Zhao Z. , Shan S. , Li H.

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tom Vol. 52, nr 3

375--384

EN

In this paper, a new multiple fiber Bragg grating (FBG) sensing system based on active mode-locking fiber laser is proposed. The active mode-locking fiber laser is composed of a linear cavity with an Fabry–Perot laser diode (F-P LD) as a reflective cavity mirror, and the erbium-doped fiber as the gain medium. Meanwhile, the F-P LD is also used as the modulating element of the fiber laser. Multiple FBGs cascaded in a long fiber are used as both the sensors in the system and the components for wavelength selection in the active mode-locking fiber laser. The capacity of the proposed sensing system to interrogate multiple FBGs in wavelength and spatial domain is investigated. The proposed sensing system has the characteristics of low cost, good stability, good compatibility, and can be used in quasi-distributed multi-point sensing.

2

A constant intensity technique to improve the performances of devices based on direct absorption spectroscopy

100%

Montori A. , Pas de M. , Giuntini M. , Siciliani Cumis de M. , Viciani S. , D’Amato F.

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tom Vol. 23, No. 1

28-32

EN

We describe an all-in-fibre apparatus for Constant Intensity Direct Absorption Spectroscopy (CIDAS) for gas concentration measurements which keeps the power of a diode laser constant along the frequency sweep. The reduction of the large variation of the laser power, connected to the frequency scan, enhances the ability of detecting small variations in a background signal, resulting in an increase of the sensitivity with respect to standard direct absorption techniques. Moreover, CIDAS allows for a real-time observation of the absorption signals without any kind of post-detection processing. The apparatus has been tested with carbon dioxide (CO₂) and methane (CH₄), around 1.57 and 1.65 μm, respectively.

3

Data encryption of optical fibre communication using pseudo-random spatial light modulation

86%

Kowalski M. , Życzkowski M.

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tom 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.

4

Monitoring of phase jitter in fibre optic time and frequency transfer systems

86%

Salwik K. , Śliwczyński Ł. , Krehlik P.

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5

Geodezyjne badania tokarki z zastosowaniem techniki światłowodowej

86%

Ćmielewski K.

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tom Vol. 9, nr 4

3-15

PL

W pracy przedstawiono badania geodezyjne tokarki z wykorzystaniem światłowodowego sygnalizatora celu. Omówiono technologię pomiarów wraz z projektem tarczy ze światłowodowym sygnalizatorem celu oraz zaprezentowano przykładowe wyniki testów tarczy oraz jej zastosowanie do pomiarów tokarki.

EN

The article presents the problem of geodetic investigations of lathe by means of target with point optical fiber indicator. This work presents the idea of fibre-optical target used for engineering objects surveying.

6

Multichannel Optical System for the Quality Control of Digital Printing

72%

Galas J. , Litwin D. , Czyżewski A. , Sitarek S. , Kołacz K.

Fibres & Textiles in Eastern Europe

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2016

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tom Vol. 24, no. 3 (117)

95--102

EN

Economical efficiency and environmental protection are key elements of modern textile treatment, where chemical fluids are digitally assigned to designated places in a printinglike process. Except arbitrarily designed colour patterns, technology provides the ability to add individual functionalities not achievable in the classical approach i.e. dip dyeing based processes. The precise deposition of chemicals or bonding components like microelectronic chips on a material substrate is crucial in producing multilayered fabrics. This paper demonstrates an optical monitoring system which enables the precise control of the deposition of functional materials or components on fabric. The optical system consists of a set of Fibre Optic Image Bundles (FOIB) connected to a single CCD line camera which enables the correlation in space and time of images acquired from different parts of the area monitored. During the deposition process the system measures fabric surface deformation and detects motion instability, and then adjusts the printing parameters accordingly.

PL

Czynniki ekonomiczne oraz ochrona środowiska odgrywają kluczową rolę w nowoczesnej technice barwienia materiałów tekstylnych, w której barwniki są nakładane w procesie przypominającym drukowanie. Poza dowolnie zaprojektowanym barwnym wzorem technologia ta pozwala na dodanie indywidualnych cech produktu, co nie jest możliwe do osiągnięcia klasycznymi metodami barwienia zanurzeniowego. Precyzyjne nakładanie na materiał barwników oraz specjalizowanych komponentów, jak na przykład, struktur elektronicznych decyduje o jakości produkcji. Artykuł przedstawia optyczny system monitorujący, który ułatwia dokładne, wielowarstwowe nakładanie na tekstylia barwników i funkcjonalnych materiałów. System optyczny jest złożony z wiązki obrazowodów dołączonych do pojedynczej liniowej kamery CCD, co pozwala na korelację w czasie i przestrzeni obrazów zbieranych z różnych obszarów kontrolnych. W trakcie nakładania warstw system mierzy deformacje powierzchni płótna oraz wykrywa zakłócenia w jego przesuwie, a następnie odpowiednio modyfikuje parametry druku.