Bandwidth and loss measurements of graded-index microstructured polymer optical fibre

The first bandwidth measurements of graded-index microstructured optical fibres are presented, demonstrating that this novel fibre geometry can provide high-bandwidth multimode polymer fibres without the need for complex doping techniques as with conventional polymer fibres.     

Rectangular-core microstructured polymer optical fibre for interconnect applications

A multimode microstructured polymer optical fibre is presented in which a large rectangular core is suspended by thin supporting bridges. Measurements of the near- and far-field patterns, the numerical aperture and polarisation mode-mixing are presented.     

微结构聚合物光纤套管法拉丝工艺

通过对微结构聚合物光纤拉丝工艺的研究,提出微结构聚合物光纤二次预制棒套管拉丝技术.为了降低光纤拉伸过程中微孔坍塌率,从光纤拉伸力和材料表面张力之间平衡的角度考虑,对拉丝炉中热区温度和长度进行控制,得到了预制棒拉丝炉和光纤拉丝炉中热区温度分布曲线.最后,通过对本体聚合法制备的椭圆芯六角对称微结构聚合物光纤预制棒的拉丝实践...     

Fabrication of microstructured polymer optical fibres

A methodology is presented suitable for the fabrication of a wide range of microstructured polymer optical fibres (mPOFs), a recent development where light guidance is achieved through the incorporation of a pattern of air channels that run the entire length of the fibre. We show that the key to good mPOF fabrication is a secondary draw oven that has tight control over the length (15–20 mm) and temperature (C) of the hot-zone while maintaining fibre draw tension high enough (50–150 g) to ensure an acceptable level of partial hole collapse (30–40%) due to surface tension effects. Diverse mPOFs with diameters in the range 200–1200 μm have been fabricated with typical standard deviations of 2–3 μm.     

Mode coupling of microstructured optical fibers using temperature-dependent nitrogen-doped silica fibers

A promising method for the diminishing of loss upon the welding of microstructured optical fibers with suspended core is proposed. The method is based on the application of the nitrogen-doped optical fiber whose thermally expanding core serves as the mode coupler. The loss related to the welding of the conventional fiber (Corning SMF-28 and OFS Clearlite 980) and the suspended-core microstructured fiber (with a core diameter of about 2 μm at wavelengths of 1060, 1310, and 1550 nm) using a conventional welding device is experimentally studied. The welding loss (less than 0.5 dB) in a wide spectral range is several times less than the loss corresponding to the existing methods for the coupling of conventional and microstructures fibers.     

Impact of polymer material properties on microstructured optical fibres

Polymer optical fibres (POFs) have historically been regarded as a poor relation to their silica counterparts because of their higher attenuation, but they also have a number of advantages, particularly when coupled with a range of properties that can be produced using micro-structures. In terms of their mechanical properties, they are lighter, remain flexible at large core sizes and can be stretched well beyond 30% without breakage. They are also biocompatible, they do not produce dangerous shards, and their low processing temperatures allow functionalized organic materials to be incorporated without decomposition. Other advantages for specific applications include better transmission properties (in the THz region) and the possibility of refractive indices that are close to that of water.     

Reduced loss in extruded soft glass microstructured fibre

The fabrication of small core high-NA soft glass microstructured optical fibres with propagation loss as low as 0.6 dB/m at 1100 nm is reported. Advances in soft glass preform extrusion and fibre fabrication have allowed the first demonstration that extrusion does not significantly contribute to the fibre loss.     

Microstructured air-silica fibres: Recent developments in modelling, manufacturing and experiment

The main modelling methods devoted to microstructured air-silica optical fibres (MOFS) are presented and discussed. Then, the specific propagation properties ofMOFS are studied in detail. Characteristics measured on fibres manufactured in our laboratory or reported in the literature are analysed. A large number of potential and demonstrated applications are presented and the obtained performances are discussed. A particular attention is given to hollow-core photonic bandgap fibres and their applications.     

Fluorescence from nano-particle doped optical fibres

The fabrication of microstructured polymer optical fibre with embedded organo-silica nano-particles and quantum dots is reported. Measurements of their in-fibre fluorescence spectra are presented.     

金属丝微结构光纤的研究进展

金属丝微结构光纤是指具有沿石英光纤轴向均匀分布着直径为纳米量级的金属丝的光纤。这种特殊结构的光纤具有传输光波以及表面等离子体波的特性,潜在用途十分广泛。介绍了金属丝微结构光纤的性质、制备方法及其研究进展。     

Chalcogenide holey fibres

The fabrication of the first non-silica holey or microstructured optical fibre is reported. The chalcogenide glass gallium lanthanum sulphide was used. Applications of such fibres include optical switching, high power-delivery, acousto-optic devices, air-guiding fibres, fibre sensors, mid-IR devices, amongst others. In addition, holey fibre technology provides an improved route towards fabricating singlemode compound glass fibres     

Microstructured optical fibre with tunable birefringence

An approach is presented for manipulating and tuning birefringence in a microstructured photonic crystal optical fibre. This is accomplished by filling certain airholes with an index tunable polymer which creates a tunable asymmetry in the index profile of the cladding. It is also demonstrated that fibre waveguides with three- and sixfold symmetry exhibit minimal birefringence     

Consideration of chiral optical fibres

Circular birefringence is a property of chiral materials. In this work, we consider the use of chiral materials in optical fibres to produce circularly birefringent optical fibres and in fibres where a contrast in circular birefringence contributes to forming the waveguide. (-)-menthyl methacrylate is also investigated as a possible material for the fabrication of such fibres.     

大模场宽频单模光子晶体光纤的设计与制备

文章对无尽单模光子晶体光纤进行了理论设计,并提出了微结构光纤的制造工艺技术和相应的光纤拉丝工艺参数,制造出了较大模场的宽频单模光子晶体光纤,该光纤的芯直径为13.1 μm,微孔直径为3.2 μm,孔间距为8.2 μm,1 550 nm波长的模场直径为14.6 μm,1 550 nm的衰减为0.6 dB/km,1 383 nm水峰为14.9 dB/km.截止波长测试和近场光强分布检验表明,该光子晶体光纤确实具备较宽的单模工作范围.     

Second zero dispersion wavelength measurement through soliton self-frequency shift compensation in suspended core fibre

Since their first development in the past decade, microstructured fibres have motivated major progress in nonlinear guided optics by offering outstanding flexibility in the design of dispersive and nonlinear properties [1]. Suspended core fibres are a new example of the extreme light confinement that is feasible in photonic crystal fibres with sub-micron core diameters [2]. This tight light confinement significantly affects the dispersion characteristics, leading to a local extremum in the group-velocity dispersion (GVD) curve and a second zero dispersion wavelength (IR-ZDW) below 2 mm. Several powerful fully vectorial techniques have been proposed to simulate the wavelength-dependent parameters of guided modes, such as the dispersion and effective area. Real microstrutured fibre structures can be taken into account through the SEM image of their fibre cross-section [3]. However, the finite accuracy of the edge detection holes and the SEM image quality itself can induce some discrepancies between caculated and real fibre parameters, especially in the prediction of the IR-ZDW which is very sensitive to the fibre geometry [4]. It is therefore of particular interest to benefit from an easy-to-implement experimental method to check for IR-ZDW value. In this Letter, we propose such a method based on the shift and control of the central wavelength of an ultra-short pulse, in the context of small core microstructured fibres. With the help of experimental results obtained in commercial PCF with two ZDWs, we illustrate two major spectral dynamics of solitons, i.e. their selffrequency shift and their frequency stabilisation. From comparison with numerical simulations, we are able to present and standardise a simple experimental method to determine the IR-ZDW, by simply measuring the frequency stabilised soliton spectrum. We also apply our technique to a suspended core fibre and experimental results are confirmed by numerical calculations of GVD curve.     

Tunable attenuator based on polymer microstructured optical fibers

The polymer microstructured optical fiber is a kind of fiber whose core and cladding are composed of air holes and organic compornoleel by a certain rule. Similar with silica microstructured optical fibers (SMOF), according to the light guide mechanism PM…     

Polymeric variable optical attenuator based on long range surface plasmon polaritons

Proposed is a polymeric variable optical attenuator based on long range surface plasmon polaritons (LRSPPs) along a thin metal stripe embedded in polymers. The device is operated by controlling radiation loss of the LRSPP mode resulting from the temperature gradient of the polymer cladding caused by a heater. For guiding LRSPPs and efficient coupling of singlemode fibres, gold stripes 20 nm thick, 4 /spl mu/m wide and 1 cm long are utilised. To obtain a long physical lifetime, the heater is formed on the top of the polymer cladding with a 200 nm Au film which is about ten times thicker than the thin metal waveguide. The fabricated device is characterised at a wavelength of 1.55 /spl mu/m, exhibiting high attenuation of less than 30 dB with an operating power of 100 mW. A fibre-to-fibre total insertion loss of 6.1 dB is achieved when using singlemode fibres.     

Dispersion minimisation in single-mode fibres over a wide spectral range

The waveguide and material dispersion are investigated for various silica-based single-mode optical fibres with arbitrary refractive-index profiles. It is shown that in the case of the doubly clad optical fibre with an index difference between the core and the outer cladding ?1=1% and that between the inner cladding and the outer ?2=?1%, the diameter of the core 2a=7.2 ?m, and the thickness of the inner cladding t=0.3a, the total dispersion is reduced within ± 1 ps/km/nm over a wide spectral range of ?=1.35?1.67 ?m.     

开放式微结构光纤研究

与传统微结构光纤相比,开放式微结构光纤不仅保持了可通过灵活的几何结构设计,从而获得优化光学传感性能的优点,利用其开放式无需预填充的特点,还可较大幅度地提高传感实时工作效率。本文对近年来出现的几种具有代表性的开放式微结构光纤进行了讨论。比较了利用开放全内反射型、WagonV％甜型及嵌入导流孔型开放式微结构光纤作为实时气液传感器时各自的优缺点。研究表明,这几种开放式微结构光纤都在气液实时传感领域显示了较为独特的优点。借助于开放式微结构光纤,可为未来高精度实时光纤传感器领域的设计提供一种较有竞争力的技术支撑。     

Photonic bandgap fibre oscillators and amplifiers

In the search for ever higher output power or energy from fibre oscillators or amplifiers a nowadays mature technology relies on enlarging the fibre mode area. Broadening of the core diameter, all other things being equal, inevitably yields a multimode fibre, thereby dramatically limiting the device usefulness. Various strategies have been deployed to design and manufacture single transverse mode fibre oscillators and amplifiers, among which making use of the so-called photonic bandgap effect to restrict the modal population seems promising. Helped by efficient and reliable numerical tools the design of large mode area singlemode photonic bandgap fibres is presented. Two fibres with 20-μm and 40-μm core diameter, both of them heavily doped with Yb³⁺ ions, have been fabricated by the widespread modified chemical vapour deposition process and are shown to behave properly when used as the core element of either continuous wave oscillators or femtosecond amplifiers. Good output beam quality (M² parameter spanning from 1.12 to 1.5 for the set of fibres studied) and high slope efficiency of 80% in cw oscillation regime are demonstrated. Furthermore the 40-μm core diameter fibre is shown to be resilient to tight bending down to 7.5-cm radius. The stack-and-draw process makes it easy to tailor the outer cladding so that a large numerical aperture can be reached. Subsequently, from this air-clad fibre, 500 fs 47 W pulses at 35 MHz are obtained from a two-stage chirped pulse amplification system.