共查询到20条相似文献,搜索用时 703 毫秒
1.
Chirped fibre Bragg grating based multiplexer and demultiplexer for DWDM applications 总被引:1,自引:0,他引:1
R. Romero O. Frazo F. Floreani L. Zhang P.V.S. Marques H.M. Salgado 《Optics and Lasers in Engineering》2005,43(9):987-994
A multiplexer/demultiplexer for 100 GHz channel spacing based on chirped fibre Bragg gratings with different bandwidths and optical circulators is presented. The spectral characteristics, specifications and operation of these passive devices are described, showing its potential use in dense wavelength division multiplexing (DWDM) applications. 相似文献
2.
F.J. McAleavey J. O'gorman J.F. Donegan J. Hegarty G. Mazé H. Poignant 《Optical and Quantum Electronics》2001,33(2):151-164
A wavelength tunable all fibre laser which utilizes Tm3+-doped fluoride fibre as a gain mechanism emitting around a wavelength of = 2.3 m is reported. Tm3+-doped fluoride fibre was coupled to a fibre Bragg grating inscribed in silica. This laser was evaluated by employing it as a wavelength tunable source in a methane gas optical sensor. A minimum gas detectivity of 100 ppm m limited by the ability to prepare low concentrations of gases was achieved. Emission wavelength control was implemented by thermally tuning the grating, although this method may prove to be too slow and cumbersome for practical use. A model describing the coupling between the silica fibre Bragg grating and the Tm3+-doped fibre was developed and integrated with a fibre laser model. This theoretical framework was used to examine the optimum silica and fluoride fibre parameters to achieve the maximum coupling between the fibres, with the aim of further reducing the fibre laser threshold. 相似文献
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Coupling characteristics of photo-induced Bragg gratings in depressed- and matched-cladding fibre 总被引:1,自引:0,他引:1
S. J. Hewlett J. D. Love G. Meltz T. J. Bailey W. W. Morey 《Optical and Quantum Electronics》1996,28(11):1641-1654
Experimental transmission spectra of ultraviolet (u.v.)-written Bragg gratings in depressed- and matched-cladding fibre are characterized and compared. In particular, we discuss how the location and strength of the spectral features vary with the degree of blazing, or angular tilt of the grating. The fine-structure detail on the short-wavelength side of the fundamental Bragg line is attributed to power coupling between the forwardpropagating fundamental (LP01) mode and discrete, backward-propagating cladding modes. Resonances corresponding to backward-propagating LP0n
and LP1n
modes are identified, and their relative strengths are compared with theoretical overlap calculations. Physical arguments are presented that explain the pronounced ghost-grating notch that appears in the transmission spectra of blazed, fibre Bragg gratings in depressed-cladding fibre. 相似文献
5.
High-energy (0.68 mJ or 55 kW) broadband (0.38 to 2.22 m) nonlinear optical conversion has been obtained in a conventional multimode optical fibre using a Nd: YAG pump laser with a direct optical fibre taper output and a taper-to-fibre coupling scheme. A taper-to-fibre launching efficiency exceeding 75% has been determined analytically and is compared with the experimental results. 相似文献
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H. Yokota M. Kobayashi H. Mineo N. Kagawa H. Kanbe Y. Sasaki 《Optics Communications》2008,281(19):4893-4898
An optical fiber grating coupler (FGC) is a fused optical fiber coupler with a tapered region in which refractive index-modulated gratings are written. In the FGC, the light with specific wavelength satisfying the Bragg condition of the grating can be dropped to one output port and other lights are transmitted to another output port when lights with various wavelengths are launched into the input port. The FGC can operate as an all-optical switch by controlling the Bragg wavelength of the grating using a third order nonlinear optical effect caused by a control light that are launched with a signal light. In this paper, an all-optical switching operation due to a third order nonlinear optical effect in an FGC is first demonstrated for a signal light with 1.55 μm-wavelength to be changed from one port of the FGC to another one by the 720 W peak of a control light from a Nd:YAG laser with 1.06 μm-wavelength. The switching efficiency obtained was 7%. It was clarified that a longer pulse length of the control light compared to the grating length is required to obtain a large Bragg wavelength shift for the switching. It was also clarified that the Bragg wavelength shift is caused by a third order nonlinear effect and a photothermal effect. A contribution of the photothermal effect was estimated. We also estimated the switching efficiency for pump power in the FGC switch. 相似文献
8.
本文基于Bragg反射光栅是一维光子晶体的一种特例结构, 提出利用一维光子晶体理论进行Bragg衍射光栅的设计并对其性能进行研究分析. 根据一维光子晶体理论, 建立了罗兰圆结构的凹面椭圆Bragg蚀刻衍射光栅, 研究了TE/TM模式下器件的分光特性以及入射角度改变对器件角色散造成的影响; 同时, 文中对比了空气介质型和金属铝线型椭圆Bragg蚀刻衍射光栅的光学性能. 研究结果表明: 选择合适的器件参数, 可以实现TE/TM模式下1.465-1.615 μm范围内波长衍射效率在95% 以上, 且空气介质型结构光栅的通道均匀性要优于金属铝线型结构光栅; 入射角在30°-60°范围内变化时, 相同入射角度下, TM模式下器件角色散大于TE模式. 基于Bragg衍射光栅设计的波分复用器是一种尺寸小、衍射效率高的新型EDG 波分复用器, 为未来密集型EDG波分复用器发展提供了一种新的设计思路. 相似文献
9.
A new WDM-PON scheme with real-time monitoring based on a time-sharing method is proposed. It uses an optical time domain reflectometer (OTDR) to monitor multiple ports by integrating an optical switch (OSW) with a dense wavelength division multiplexer (DWDM) at the optical line terminal (OLT) site. Each downstream signal and its corresponding monitoring signal are separated by m times the free-space range (FSR) of an array waveguide grating (AWG). A bit error rate (BER) test in 2.5 Gb/s × 27 km is performed with and without turning on the OTDR. A small power penalty of 0.7 dB is observed compared to the back-to-back measurement. 相似文献
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Compact superstructure fibre Bragg gratings for the generation of ultra-high speed optical pulse bursts are reported. The gratings are equivalent in response to multi-pass superimposed chirped fibre Bragg gratings (SI-CFBGs), but an arbitrary sequence of consecutive gratings can be replicated in a single fabrication step using a simple trigonometric amplitude-phase function. SI-CFBGs are fabricated in photosensitive optical fibre and the time-resolved reflection of a 10 GHz picosecond pulse train is measured via frequency-resolved optical gating and optical sub-harmonic sampling detection techniques. The experimental results are compared to the theoretically simulated grating response and good agreement is found. 相似文献
12.
Masao Kawachi 《Optical and Quantum Electronics》1990,22(5):391-416
A marriage of optical fibre fabrication technology and LSI microfabrication technology gave birth to fibre-matched silica waveguides on silicon: thick glass layers of high-silica-content glass are deposited on silicon by flame hydrolysis, a method originally developed for fibre preform fabrication. Silica channel waveguides are then formed by photolithographic pattern definition processes followed by reactive ion etching. This high silica (HiS) technology offers the possibility of integrating a number of passive functions on a single silicon chip, as well as the possibility of the hybrid integration of both active and passive devices on silicon. This paper reviews the NTT HiS technology and its application to integrated-optic components such as optical beam splitters, optical switches, wavelength-division multi/demultiplexers and optical frequency-division multi/demultiplexers. The clear and simple waveguide structures produced by the HiS technology make it possible to design and fabricate these components with high precision and excellent reproducibility. 相似文献
13.
Study of the behaviour of the fibre Bragg grating fabricated with cladding mode suppression fibre 下载免费PDF全文
One effective method for suppression of coupling from guided optical modes into cladding modes in an optical fibre Bragg grating is to use cladding mode suppression fibre. In this specially engineered fibre, the grating is written into the core and the inner cladding, both of which are photosensitive. A theory is presented in this paper to analyse the spectral characteristics of this kind of gratings. A fibre Bragg grating was experimentally fabricated with this kind of photosensitive fibre (PS-RMS-50 from StockerYale). It is shown both theoretically and experimentally that such gratings exhibit strong suppression of the coupling between core mode and cladding mode. The experimental result is in good agreement with the theoretical analysis. 相似文献
14.
Jaemyoung Lee 《Optik》2010,121(17):1570-1572
We propose a simple optical preprocessing for optical clock recovery using a fiber Bragg grating (FBG) filter. In the proposed scheme, the signal preprocessing is performed by suppressing the carrier component through the FBG filter, and experiment shows that the clock component is larger than about 10 dB compared with other rf components within a distance of from the clock frequency component. 相似文献
15.
Double clad aluminosilicate optical fibre doped with
neodymium ions was obtained. Aluminosilicate glasses with low silica (25 mol%)
content possess very good optical, thermal and mechanical properties. Simultaneously they are characterized by high solubility
of rare
earth elements. A set of physical measurements including: DTA, DSC, DL
analysis, absorption spectroscopy and thermo-physical properties (thermal
stability parameters, refractive index, thermal expansion coefficient,
microhardness, density and molar volume) were determined. Double-crucible
drawing technique was applied to obtain neodymium doped double clad optical
fibre with
. Luminescence spectra of aluminosilicate glass and fibre
doped with Nd3 + ions are presented. 相似文献
16.
A self-frequency-locked laser in a 1.55 m band is demonstrated by adding a segment of samarium-doped fibre (SDF) into an erbium-doped fibre (EDF) ring laser cavity. The narrow band output signal, with a 3 dB down line width of less than 0.15 nm and a side-mode suppression ratio larger than 30 dB, is nearly polarization independent. A multiwavelength EDF ring laser source, using a 1×n synchronous optical switch and n segments of SDF with different lengths, is proposed. 相似文献
17.
J. Kaňka 《Optical and Quantum Electronics》1987,19(3):191-200
The time-independent diffusion equation that describes an optical power flow in an axially perturbed multimode fibre with a lossy cladding is solved. On this basis the attenuation of plastic-clad silica (PCS) fibres depending on cladding loss, mode coupling due to fibre perturbation, launching conditions and fibre length is investigated by means of computer modelling. This involves not only attenuation properties of PCS fibres by themselves, but also how they are seen by the backscattering measurement technique. 相似文献
18.
基于光纤光栅的光子器件及其在波分复用系统中的应用 总被引:4,自引:0,他引:4
本文报道了光纤光栅外腔激光器、光纤光栅解复用器、光纤光栅滤波器、解复用滤波器和分/插复用器(OADM)等在全光通信网中有应用潜力的新型光子学器件的实验结果,并演示了这些器件的功能和基于这些器件的4路符合ITU波长标准,间隔约为1.6nm,速率为4×155Mbit/s的密集波分复用传输。 相似文献
19.
We propose a novel optical bit-pattern recognition employing an Opto-VLSI processor in conjunction with an array of fibre Bragg gratings (FBGs) with different Bragg wavelengths and a coherent-to-incoherent light converter. The FBG array slices the spectrum of the incoherent optical header and provides wavelength-dependent time delays, whereas the Opto-VLSI processor generates wavelength intensity profiles that match specific bit patterns. The recognition of 8-bit optical patterns is experimentally demonstrated at 2.2 Gb/s by showing that the correlator produces an autocorrelation waveform of high peak whenever the input bit pattern matches the wavelength intensity profile. 相似文献
20.
T. Nagahori M. Itoh I. Watanabe J. Hayashi H. Honmou T. Uji 《Optical and Quantum Electronics》1992,24(4):S479-S490
An optical fibre parallel interface has been developed for card-cage to card-cage and board-to-board interconnections, representing a practical and promising optical interconnection. For a system design of a 12 channel, 150 Mbits–1 ch–1 optical parallel interface over a distance of 100 m, it is shown that the choice of a long wavelength LED/PD array with graded index optical fibre array meets the requirements for both power budget and skew limitation over this transmission distance. A 7 mm thick compact package transmitter and receiver module was developed, employing a Zn-doped, mesa structure, 1.3m LED array and an isolated InGaAs PD array. An optical parallel transmission experiment over 100 m was successfully demonstrated using these modules. 相似文献