We provide a convenient way to actively control the wavelength conversion of probe waves based on the soliton dynamics in the As2S3 fibers. In this paper, it is found by numerical calculation that wavelength conversion occurs in the frequency domain due to the existence of refractive index barrier. By adjusting the collision position of pump pulse and probe pulse to realize the conversion of probe pulse wavelength, the effect of the power and the incident wavelength of the probe wave on the wavelength conversion are also discussed. This frequency domain conversion is of great use in the mid-infrared region, for example, all-optical conversion switches.
2
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
All normal dispersion (ANDi) and highly nonlinear chalcogenide glass photonic crystal fiber (PCF) is proposed and numerically investigated for a broad, coherent and ultra-flat mid-infrared supercontinuum generation. The proposed PCF consists of a solid core made of Ga₈Sb₃₂S₆₆ glass surrounded by seven rings of air holes arranged in a triangular lattice. We show by employing the finite difference frequency domain (FDFD) method that the Ga₈Sb₃₂S₆₆ PCF dispersion properties can be engineered by carefully adjusting the air holes diameter in the cladding region and ANDi regime is achieved over the entire range of wavelengths with a zero chromatic dispersion around 4.5 μm. Moreover, we demonstrate that injecting 50 fs width and 20 kW peak power laser pulses (corresponding to a pulse energy of 1.06 nJ) at a pump wavelength of 4.5 μm into a 1 cm long ANDi Ga₈Sb₃₂S₆₆ PCF generates a broad, flat-top and perfectly coherent SC spectrum extending from 1.65 μm to 9.24 μm at the 20 dB spectral flatness. These results make the proposed Ga₈Sb₃₂S₆₆ PCF an excellent candidate for various important mid-infrared region applications including mid-infrared spectroscopy, medical imaging, optical coherence tomography and materials characterization.
This work describes the suitability of a nano-dimension slot with low index material in the core region to achieve a highly nonlinear, polarization maintaining and dispersion compensating photonic crystal fiber. Our design is composed of a spiral shaped photonic crystal fiber with an elliptical slot made of silicon nanocrystals in the core region. The simulated results show that high nonlinear coefficients at the 1.55 μm wavelength for quasi-TE mode and quasi-TM mode are found to be equal to 1348 and 638 W–1m–1, respectively. The proposed design offers high birefringence up to 0.2503 and large negative dispersion value –1228 ps/nm/km. The proposed fiber has immense potential for realization of all-optical signal processing devices/networks and sensing applications while maintaining its polarization.
In this paper, a microstructured optical fiber with dual core was proposed which is known as photonic crystal fiber. Specific optical properties of a dual-core photonic crystal fiber were used to obtain high birefringence, small beat length, flattened dispersion, for different values of structural parameters varied over a wide range of wavelength and analyzed for application such as temperature and pressure sensors. The sensitivity of the temperature sensor is calculated as 20 pm/°C for 6 cm fiber, the sensitivity of the pressure sensor for a range from 0 to 1000 kPa is calculated as –10.5 nm/MPa.
A multi-parameter sensor with enhanced sensitivity based on magnetic fluids infiltrated photonic crystal fiber is proposed. The sensing performances are investigated using the mode coupling theory and finite element method. Four symmetrical defective channels are assembled into the photonic crystal fiber to produce two resonant transmission dips λCV and λCH in vertical and horizontal directions, respectively. Each dip can be split into two relatively shallow dips (λCV1, λCV2 or λCH1, λCH2) when the photonic crystal fiber is bent. Interestingly, the values of (λCH2 – λCH1) and (λCV2 – λCV1) are associated with corresponding bend-curvature but almost unaffected by external temperature or magnetic field. On the contrary, the values of (λCH2 + λCH1)/2 and (λCV2 + λCV1)/2 are sensitive to temperature or magnetic field regardless of the bending condition. Based on above characteristics and the dependence of the magnetic fluids refractive index on temperature and magnetic field, the proposed sensor can measure not only the bend-curvature and bend-direction, but also the temperature and magnetic field.
A polarization photonic crystal fiber based on surface plasmon resonance is proposed in this paper. The photonic crystal fiber with gold coated holes is studied through using the finite element method. The impacts of structural parameters on the resonance characteristics are discussed. Numerical simulations show that the resonance wavelength can be modulated by changing the parameters of the air holes and thickness of gold layer. At the resonance wavelength 1550 nm, the loss is 3.8045 dB/m in x-polarization and the loss is 28464 dB/m in y-polarization by adjusting the size of the gold-coated holes and the place of air holes. Results show that the loss of y-polarized mode is much larger than the loss of x-polarized mode. The y-polarized mode is suppressed, and only x-polarized mode can be guided at the resonance wavelength of y-polarized mode. The results indicate that the mode polarized in one direction can be filtered out selectively by adjusting the diameter of air holes, and the filtering effect in a communication band is achieved.
For optimum fusion splicing process of a photonic crystal fiber, the collapsing of the air holes at any photonic crystal fiber is the key point of either increasing or decreasing the total splice loss. In this paper, an experimental study has been carried out to investigate the relation between total splice loss or total fiber attenuation due to splice loss and the length of the collapsed region of the air holes. This is done by splicing ESM-12B photonic crystal fiber between two equal lengths of single mode fibers and measuring the attenuation at different arc times and arc powers. The results showed that the increase in the length of the collapsed air holes region results in higher loss, therefore, higher fiber attenuation.
A new design of a guiding-index photonic crystal fiber which possesses a beam shaping effect and flexible control of dispersion has been proposed in this paper. It can shape a Gaussian beam into a circular hollow beam with certain dimension, which can be used in optical communication systems with a Cassegrain antenna to improve transmission efficiency by avoiding the loss of energy caused by the subreflector center reflection. In addition, its dispersion and confinement loss can be changed in a broad range by slightly adjusting structural parameters under condition that the hollow beam dimension remains about the same. Fairly practical properties, zero dispersion or flattened dispersion, can be obtained when structural parameters are set appropriately. A series of models with different parameters are analyzed and compared. Results of numerical simulation show that the ultra-low dispersion of 1.802 ps/km/nm can be obtained when λ = 1.31 μm. Several modest design parameters are given as well.
A broad review is given of microstructured fiber optics components - light guides, image guides, multicapillary arrays, and photonic crystal fibers - fabricated using the stack-and-draw method from various in-house synthesized oxide soft glasses at the Glass Department of the Institute of Electronic Materials Technology (ITME). The discussion covers fundamental aspects of stack-and-draw technology used at ITME, through design methods, soft glass material issues and parameters, to demonstration of representative examples of fabricated structures and an experimental characterization of their optical properties and results obtained in typical applications. Specifically, demonstrators include microstructured image guides providing resolution of up to 16000 pixels sized up to 20 μm in diameter, and various photonic crystal fibers (PCFs): index-guiding regular lattice air-hole PCFs, hollow core photonic bandgap PCFs, or specialty PCFs like highly birefringent microstructured fibers or highly nonlinear fibers for supercontinuum generation. The presented content is put into context of previous work in the area reported by the group of authors, as well as other research team.
The phenomenon of optical birefringence in optical fibers is caused by external factors and stress induced by the manufacturing process. This optical birefringence makes it difficult to apply optical fibers as a polarimetric sensors head. Author of this paper, proposes the application of index guiding photonic crystal fibers because stress values in a fiber core caused by internal and external factors are lower. In this paper investigation results extended in comparison with the previous author’s investigations are presented. This extension relies on investigation of magnetooptic for wavelength 405 nm. On the basis of experimental results optimal work points of optical sensing fibers were determined.
W publikacji przedstawiono prace wykonane w Instytucie Technologii Materiałów Elektronicznych dotyczące wytworzenia światłowodu fotonicznego wykonanego ze szkła fosforanowego z przeznaczeniem do konstrukcji lasera włóknowego. Wykonane zostały wytopy szkieł domieszkowanych i niedomieszkowanych. Na podstawie przeprowadzonych pomiarów spektralnych przeprowadzono analizę własności absorpcyjnych i emisyjnych wytworzonego szkła domieszkowanego. Zweryfikowano parametry dopasowania szkieł domieszkowanego i niedomieszkowanego pod kątem właściwości reologicznych i współczynnika załamania. Wytworzone zostało włókno laserowe ze szkła fosforanowego o strukturze dwupłaszczowej (double-clad) w pełni wykonanej w technologii fotonicznej. Poprzez zastosowanie włókna o powiększonej średnicy rdzenia uzyskano znaczne zwiększenie absorpcji promieniowania pompy i skrócenie długości lasera. Ponadto stosując płaszcz powietrzny osiągnięto rekordową wartość apertury numerycznej falowodu pompy we włóknie typu double-clad ze szkła fosforanowego wynoszącą 0,91. Maksymalna moc generacji w laboratoryjnym układzie lasera we włóknie o długości 19 cm wyniosła 12,4 W przy sprawności różniczkowej 42,8 %.
EN
This paper presents the research work on a Yb3+ doped photonic crystal fiber laser with an extended mode area made of phosphate glass carried out at ITME. By increasing the mode area we obtained the laser with a higher power level and a shorter fiber length than before. The doped and undoped glass was manufactured and subsequently the measurements of optical and rheological properties were done. The analysis of both absorption and emission of the doped glass was performed. The fiber with the extended mode area was manufactured and its passive properties were examined. The numerical aperture of the pump waveguide was found to be very high and equaled 0.91, which is a record-breaking value for phosphate photonic structures and, at the same time, one of the highest values obtained for structures made of silica. We achieved laser generation from the 19 cm fiber with the maximum power of 12.4 W and the slope efficiency of 42.8 %.
12
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
The properties of a fiber optic Sagnac loop with a polarization maintaining photonic crystal fiber are presented, which is utilized as an optical wavelength demodulator. Owing to the use of a photonic crystal fiber, which has high birefringence and a very low temperature coefficient of birefringence, a temperature-stable optical wavelength demodulator circuit was obtained. The constructed demodulator was applied in a fiber optic force sensor with a Bragg grating. The nonlinearity error of the sensor with the demodulator does not exceed 1 %.
PL
Przedstawiono właściwości światłowodowej pętli Sagnaca ze światłowodem fotonicznym przenoszącym polaryzację wykorzystanej jako optyczny demodulator długości fali. Dzięki zastosowaniu światłowodu fotonicznego o wysokiej dwójłomności i bardzo małym współczynniku temperaturowym dwójłomności uzyskano stabilny temperaturowo układ demodulatora długości fali optycznej. Zastosowano wykonany demodulator w światłowodowym czujniku siły z siatką Bragga. Błąd nieliniowości tego czujnika z demodulatorem nie przekracza 1 %.
Omówiono wybrane aspekty związane z rozwojem badań nad przyrządami i zintegrowanymi systemami fotonicznymi, przeznaczonymi w szczególności do współpracy z przezroczystymi sieciami optycznymi nowych generacji, transmisją i przetwarzaniem danych.
EN
The paper presents selected areas of research on devices and integrated photonic systems, in particular those intended for use in new generation transparent optical networks, data transmission and processing.
Properties of two different photonic crystal fibers (PCF) were characterized, enabling comparisons. Properties investigated included spectral attenuation, polarization mode dispersion (PMD), optical time domain reflectometer characteristics, elastooptic factor describing transmission delay induced by axial strain plus effects of temperature cycling and fiber twist on PMD and loss. In particular, temperature and twist dependence of PMD was different for each fiber tested. For optical measurements, fibers were fusion spliced to pigtails with standard telecom single mode fibers. PCF splicing procedures and solutions adopted to minimize collapse of holes during arc fusion and splice loss are presented. It was found that fusion splicing procedure must be individually tailored to each combination of fibers.
The paper presents optical measurements - spectral loss, OTDR and PMD, temperature cycling and mechanical tests - bending, twist and crush, performed on Yb-doped single mode fibers and small-core photonic crystal fibers (PCF). Several issues related specifically to characterization of such specialty fibers, like measurement errors and artifacts as well as coupling of test instruments to samples are presented. Of particular importance is reliable and low-loss fusion splicing of specialty fibers to standard single mode fibers (SMF), as most commercially available fiber test instruments are fitted with SMF interfaces only.
Przedstawiono koncepcję oraz obliczenia numeryczne światłowodu fotonicznego typu holey do lokalizacji miejsca zaburzenia bazującego na różnicy prędkości grupowej modów propagujących się w różnych obszarach włókna. Zaletą światłowodu fotonicznego w stosunku do włókien konwencjonalnych jest możliwość uzyskania większej różnicy prędkości grupowych oraz większa czułość na zaburzenia mikrozgięciowe.
EN
In this paper the conception as well as computational results of photonics crystal fibres for localization sensor are shown. Conception of the sensor based on the group velocity difference of the propagating modes in the different fibre's regions. One of the big advantage of the PCF's is a possibility to obtain bigger group velocity difference as well as higher bending sensitivity in comparison with the conventional fibres.
Światłowody fotoniczne stanowią nową klasę włókien optycznych charakteryzujących się wieloma nowymi i ciekawymi właściwościami. Jedną z najciekawszych jest możliwość dopasowywania ich parametrów przez kształtowanie geometrii włókna. Przedstawiono ideę działania światłowodów fotonicznych, omówiono ich rodzaje, budowę i własności, głównie pod względem aplikacji telekomunikacyjnych. Przedstawiono również skrótowo metody produkcji włókien fotonicznych.
EN
Photonic crystal fibers (PCFs) are the new class of fiber optics that are characterized by a set of new interested features. The possibility of tailoring of the parameters through shaping of the fiber, geometry is one of the most interesting feature. The idea of PCFs, their structures and features in the light of using them in telecommunication applications are presented as well. The short characteristic of manufacturing methods of PCFs are also presented in the paper.
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.