共查询到20条相似文献,搜索用时 15 毫秒
1.
We propose and demonstrate hydrophobic photonic crystal fibers (PCFs). A chemical surface treatment for making PCFs hydrophobic is introduced. This repels water from the holes of PCFs, so that their optical properties remain unchanged even when they are immersed in water. The combination of a hollow core and a water-repellent inner surface of the hydrophobic PCF provides an ultracompact dissolved-gas sensor element, which is demonstrated for the sensing of dissolved ammonia gas. 相似文献
2.
Elliptical-hole photonic crystal fibers 总被引:9,自引:0,他引:9
We study the dispersive properties of photonic crystal fibers (PCF's) with elliptical air holes. The unusual guidance of PCF leads to novel behavior of the birefringence, group-velocity walk-off, and dispersion parameters, including the possibility of zero walk-off with high birefringence in the single-mode regime. A number of these effects are closely tied to the underlying radiation states of the air-hole lattice. 相似文献
3.
Highly birefringent photonic crystal fibers 总被引:46,自引:0,他引:46
Ortigosa-Blanch A Knight JC Wadsworth WJ Arriaga J Mangan BJ Birks TA Russell PS 《Optics letters》2000,25(18):1325-1327
We report a strongly anisotropic photonic crystal fiber. Twofold rotational symmetry was introduced into a single-mode fiber structure by creation of a regular array of airholes of two sizes disposed about a pure-silica core. Based on spectral measurements of the polarization mode beating, we estimate that the fiber has a beat length of approximately 0.4 mm at a wavelength of 1540 nm, in good agreement with the results of modeling. 相似文献
4.
All-solid silica-based photonic crystal fibers 总被引:1,自引:0,他引:1
Ming-Yang Chen 《Optics Communications》2006,266(1):151-158
An index-guiding all-solid photonic crystal fiber (PCF) composed entirely of silica material is proposed in this paper. The core of this optical fiber is composed of pure silica, and the cladding consists of doped silica rod in the background of pure silica. The dependence of confinement loss on the diameter of the doped rods, the number of doped-rod rings, and the doping level is investigated numerically. In addition, the proposed fiber possesses a shorter cutoff wavelength as compared with the air/silica PCF, which is directly confirmed by the V parameter, and explained based on a scalar approximation method. Furthermore, the bending loss for the fiber is predicted. A low-loss single-mode all-solid silica-based PCF with a large-mode-area is possible by the appropriate selection of configuration parameters. 相似文献
5.
We determined theoretically a phase elongation sensitivity
of the Photonic Crystal Fibers by means of the Multipole Method. The
sensitivity was confirmed experimentally with good agreement for LMA-8 PCF. 相似文献
6.
7.
The tomographic reconstruction of the refractive index distribution in a large-mode-area photonic fiber is presented. The results of the diffraction tomographic algorithm and classical filtered backprojection method are compared. Additionally, the application of the synthetic aperture technique to tomographic interferometry, as a tool for resolution enhancement, is presented and discussed. 相似文献
8.
9.
All-glass endless single-mode photonic crystal fibers 总被引:1,自引:0,他引:1
Endless single-mode fibers, which remain single mode over their entire range of guidance, are, to the best of our knowledge, the first reported unique application of photonic crystal fibers. These endless single-mode fibers are made by omitting a single air hole in a periodic array of small air holes in a background silica glass. The feasibility of all-glass endless single-mode photonic crystal fibers where the air holes are replaced by a glass with vanishingly small refractive index contrast relative to silica is first studied theoretically and then demonstrated experimentally. This new all-glass design enables not only ease and consistency of fabrication but also the convenience to be handled and spliced like conventional fibers. 相似文献
10.
Group-velocity dispersion in photonic crystal fibers 总被引:12,自引:0,他引:12
The dispersion properties of photonic crystal fibers are calculated by expression of the modal field as a sum of localized orthogonal functions. Even simple designs of these fibers can yield zero dispersion at wavelengths shorter than 1.27 mum when the fibers are single mode, or a large normal dispersion that is suitable for dispersion compensation at 1.55 mum. 相似文献
11.
O. Frazo J.L. Santos F.M. Araújo L.A. Ferreira 《Laser \u0026amp; Photonics Reviews》2008,2(6):449-459
A review of optical fiber sensing demonstrations based on photonic crystal fibers is presented. The text is organized in five main sections: the first three deal with sensing approaches relying on fiber Bragg gratings, long‐period gratings and interferometric structures; the fourth one reports applications of these fibers for gas and liquid sensing; finally, the last section focuses on the exploitation of nonlinear effects in photonic crystal fibers for sensing. 相似文献
12.
Introduction to nonlinear photonic crystal fibers 总被引:1,自引:0,他引:1
Kim P. Hansen 《Journal of Optical and Fiber Communications Reports》2005,2(3):226-254
13.
J. Milanovic J. Heersink Ch. Marquardt A. Huck U. L. Andersen G. Leuchs 《Laser Physics》2007,17(4):559-566
We report on the generation of polarization squeezing by employing intense, ultrashort light pulses in a single pass method
in photonic crystal fibers. We investigated the squeezing behavior near the zero-dispersion wavelength and in the anomalous
dispersion regime by using two distinct fibers. We observed a maximal squeezing at 810 nm of −3.3 ± 0.3 dB with an excess
noise of +16.8 ± 0.3 dB in the anomalous regime. Correcting for linear and interference losses between the polarization modes,
this corresponds to −6 ± 1 dB. The ratio of squeezing to excess noise indicates the creation of a much purer state; this ratio
indeed lies an order of magnitude below those squeezing experiments that exploit traditional fibers [1]. We attribute this
increased state of purity to increased effective nonlinearity and to the reduction of scattering on acoustic modes in the
fiber.
Original Text ? Astro, Ltd., 2007. 相似文献
14.
Fabrication of fiber-embedded multi-core photonic crystal fibers 总被引:2,自引:0,他引:2
A novel fabrication method of multi-core photonic crystal fibers is proposed on the basis of a fiber-embedded technique. A taper tower is used to modify the structures of the fiber preform, and four steps of fiber fabrication and different structures of fiber samples are given. The mode structures and beating characteristics of a photonic crystal fiber sample with two successive cores are investigated in detail with the help of a supercontinuum light source, a charge-coupled device (CCD) camera, and an optical spectrum analyzer. The test results show a clear beating phenomenon between two orthotropic polarization modes with a 2.8-nm peak interval in wavelength. 相似文献
15.
Numerical analysis of multicore photonic crystal fibers 总被引:2,自引:0,他引:2
A Galerkin's method-based numerical procedure is extended to obtain the modal field distribution of multicore photonic crystal fibers for the first time to our knowledge, which can reveal how the air hole size influences the mode coupling and how the coupling strength varies with wavelength. These results will be helpful in the future design of multicore photonic crystal fibers with proper guidance properties. 相似文献
16.
We reported on the supermode selection of total-internal-reflection photonic crystal fibers (PCFs) with linearly and circularly distributed multicores. The supermode characteristics were investigated using a full-vector finite-element method (FEM). The near and far-field patterns of supermodes supported by the multicore photonic crystal fiber were presented. A Talbot cavity was employed to select the wanted supermode. 相似文献
17.
We propose the realization of single-polarization operation in highly birefringent photonic crystal fibers. The suppression of one of the polarization states is realized by introducing index-matched cladding defect waveguides. The leakage loss of the index-matched polarization state can be enhanced by nearly 4 orders of magnitude. In particular, polarization-dependent loss larger than 2.97 dB/m with transmission loss lower than 0.03 dB/m in a wavelength region ranging from 1.54 to 1.566 microm can be realized in one such fiber. 相似文献
18.
By using a multipole moment approach, we analyze the loss of an air-core photonic crystal fiber and demonstrate that it is possible reduce the transmission loss that is due to photon radiation leakage through the photonic crystal cladding to a level below 0.01 dB/km, with eight rings of air holes. An analogy is drawn between air-core photonic crystal fiber modes and Bragg fiber modes. The influence of material absorption in the silica glass is discussed. 相似文献
19.
Control of dispersion in photonic crystal fibers 总被引:1,自引:0,他引:1
P.J. Roberts B.J. Mangan H. Sabert F. Couny T.A. Birks J.C. Knight P.St.J. Russell 《Journal of Optical and Fiber Communications Reports》2005,2(5):435-461
Photonic crystal fibers (PCFs) exploit the large index difference between air and glass to achieve modal properties unattainable
by conventional fiber techniques. 相似文献
20.
Side pumping of double-clad photonic crystal fibers 总被引:2,自引:0,他引:2
Side pumping of double-clad photonic crystal fibers is experimentally demonstrated. Optical access to the multimode cladding is obtained by collapsing the airholes over a short length of fiber while leaving the inner single-mode core undisturbed. Coupling efficiencies greater than 90% are obtained. A side-pumped Yb fiber laser with a slope efficiency of 81% is demonstrated with this method. 相似文献