Simple And Temperature-insensitive Pressure Sensing Based On A Hollow-core Photonic Crystal Fiber

The sensitivity to pressure of lossy air-guided modes in a commercial hollow-core photonic crystal fiber was experimentally exploited to develop a novel pressure sensor. The transmission of these modes was directly modulated by the measurand, which makes the interrogation system very simple. Using a supercontinuum source, these specific modes were identified within the visible spectral range and correspond to narrow transmission windows well away from the fiber's main bandgap, centered around 1550 nm. The origin of these windows is being investigated but is likely to be related to cladding bandgaps. One of these windows, around 633 nm, was used for the analysis presented in this paper. An attenuation increase was observed when pressure was applied to a ∼3-cm long cell, which was traversed by the fiber. The attenuation reached 5 dB with 300kgf/cm2 gauge pressure. The transmission was found to be insensitive to temperature up to 100°C, which is a highly attractive feature for sensing applications. It was also found that much higher sensitivities (a few dB attenuation with ∼0.5kgf/cm2 gauge pressure) could be obtained when pressure was internally applied to the fiber microstructure. This fact allows for the construction of sensors with a wide range of sensitivities, which can, thus, suit different applications. Transmission within the infrared bandgap was insensitive to pressure and can serve as a reference. © American Institute of Physics.1055129132Knight, J.C., (2003) Nature, 424, pp. 847-851Alkeskjold, T.T., Lægsgaard, J., Bjarklev, A., Hermann, D.S., Broeng, J., Li, J., Gauza, S., Wu, S.-T., (2006) Appl. Opt, 45, pp. 2261-2264Cordeiro, C.M.B., de Matos, C.J.S., dos Santos, E.M., Bozolan, A., Ong, J.S.K., Facincani, T., Chesini, G., Brito Cruz, C.H., (2007) Meas. Sci. Technol, 18, pp. 3075-3081Jensen, J.B., Pedersen, L.H., Hoiby, P.E., Nielsen, L.B., Hansen, T.P., Folkenberg, J.R., Riishede, J., Bjarklev, A., (2004) Opt. Lett, 29, pp. 1974-1976Krohn, D.A., Pressure Sensors (2000) Fiber Optic Sensors, pp. 143-151. , Research Triangle Park: Instrument Society of AmericaXu, M.G., Reekie, L., Chow, Y.T., Dakin, J.P., (1993) Electron. Let, 29, pp. 398-399Hsu, Y.S., Wang, L., Fung Liu, W., Chiang, Y.J., (2006) IEEE Photon. Technol. Let, 18, pp. 874-876Nasilowski, T., (2005) Appl. Phys. B, 81, pp. 325-331Bock, W.J., Chen, J., Eftimov, T., Urbanczyk, W., (2006) IEEE T. Instrum. Meas, 55, pp. 874-876Shinde, Y.S., Gahir, H.K., (2008) IEEE Photon. Technol. Let, 20, pp. 279-28

Complex terrain experiments in the New European Wind Atlas

The New European Wind Atlas project will create a freely accessible wind atlas covering Europe and Turkey, develop the model chain to create the atlas and perform a series of experiments on flow in many different kinds of complex terrain to validate the models. This paper describes the experiments of which some are nearly completed while others are in the planning stage. All experiments focus on the flow properties that are relevant for wind turbines, so the main focus is the mean flow and the turbulence at heights between 40 and 300 m. Also extreme winds, wind shear and veer, and diurnal and seasonal variations of the wind are of interest. Common to all the experiments is the use of Doppler lidar systems to supplement and in some cases replace completely meteorological towers. Many of the lidars will be equipped with scan heads that will allow for arbitrary scan patterns by several synchronized systems. Two pilot experiments, one in Portugal and one in Germany, show the value of using multiple synchronized, scanning lidar, both in terms of the accuracy of the measurements and the atmospheric physical processes that can be studied. The experimental data will be used for validation of atmospheric flow models and will by the end of the project be freely available. This article is part of the themed issue ‘Wind energy in complex terrains’

Post-processing Multicore Photonic Crystal Fibers For Locally Coupling Selected Core Pairs

Coupling selected cores among otherwise decoupled multiple cores in photonic crystal fibers is demonstrated via the use of differential pressure and heat for local processing. Complex interferometer assemblies for all-fiber devices may be achieved. © OSA/CLEO 2011.Friberg, S.R., Ultrafast all-optical switching in a dual-core fiber nonlinear couples (1987) Appl. Phys. Lett., 51, pp. 1135-1137Saitoh, F., Saitoh, K., Koshiba, M., A design method of a fiber-based mode multi/demultiplexer for mode-division multiplexing (2010) Opt. Express, 18, pp. 4709-4716Reichenbach, K.L., Xu, C., Numerical analysis of light propagation in image fibers or coherent fiber bundles (2007) Opt. Express, 15, pp. 2151-2165Gauden, D., Mechin, D., Vaudry, C., Yverbault, P., Pureur, D., Variable optical attenuator based on thermally tuned Mach-Zehnder interferometer within a twin core fiber (2004) Opt. Commun., 231, pp. 213-216Kim, B., Kim, T.-H., Cui, L., Chung, Y., Twin core photonic crystal fiber for in-line Mach-Zehnder interferometric sensing applications (2009) Opt. Express, 17, pp. 15502-15507Harhira, A., Lapointe, J., Kashyap, R., A Simple Bend Sensor Using a Twin Core Fiber Mach-Zehnder Interferometer (2010) Latin America Optics and Photonics Conference, , OSA Technical Digest (CD) (Optical Society of America, paper TuF3Villatoro, J., Simple all-microstructured-optical-fiber interferometer built via fusion splicing (2007) Opt. Express, 15, pp. 1491-1496Witkowska, A., Lai, K., Leon-Saval, S.G., Wadsworth, W.J., Birks, T.A., All-fiber anamorphic core-shape transitions (2006) Opt. Lett., 31, pp. 2672-2674Gerosa, R.M., In-fiber Modal Mach-zehnder Interferometer Based on Locally Post-processing the Core of a Photonic Crystal Fiber (2010) Latin America Optics and Photonics Conference, , OSA Technical Digest (CD) (Optical Society of America, paper ThF

Selectively Coupling Core Pairs In Multicore Photonic Crystal Fibers: Optical Couplers, Filters And Polarization Splitters For Space- Divisionmultiplexed Transmission Systems

Selective coupling a single pair of cores in a photonic crystal fiber with multiple, initially decoupled, cores is demonstrated through the use of a technique to locally post-process the fiber cross section. Coupling occurs when the hole between the selected core pair is collapsed over a short fiber section, which is accomplished by heating the section while the hole is submitted to an air pressure that is lower than that applied to all other holes in the microstructure. The demonstrated couplers present an estimated insertion loss of ∼1 dB and exhibit spectral modulations with a depth of up to 18 dB and a high polarization sensitivity that can be exploited for polarization splitting or filtering in space-division-multiplexed optical interconnection and telecommunication links. © 2012 Optical Society of America.20272898128988Gauden, D., Mechin, D., Vaudry, C., Yvernault, P., Pureur, D., Variable optical attenuator based on thermally tuned Mach-Zehnder interferometer within a twin core fiber (2004) Opt. Commun., 231 (1-6), pp. 213-216Kim, B., Kim, T.-H., Cui, L., Chung, Y., Twin core photonic crystal fiber for in-line Mach-Zehnder interferometric sensing applications (2009) Opt. Express, 17 (18), pp. 15502-15507Harhira, A., Lapointe, J., Kashyap, R., A Simple Bend Sensor Using a Twin Core Fiber Mach-Zehnder Interferometer (2010) Latin America Optics and Photonics Conference, OSA Technical Digest (CD), , Optical Society of America, paper TuF3Zhou, A., Li, G., Zhang, Y., Wang, Y., Guan, C., Yang, J., Yuan, L., Asymmetrical twin-core fiber based michelson interferometer for refractive index sensing (2011) J. Lightwave Technol., 29 (19), pp. 2985-2991Michaille, L., Taylor, D.M., Bennett, C.R., Shepherd, T.J., Ward, B.G., Characteristics of a Q-switched multicore photonic crystal fiber laser with a very large mode field area (2008) Opt. Lett., 33 (1), pp. 71-73Fang, X.-H., Hu, M.-L., Liu, B.-W., Chai, L., Wang, C.-Y., Zheltikov, A.M., Generation of 150 MW, 110 fs pulses by phase-locked amplification in multicore photonic crystal fiber (2010) Opt. Lett., 35 (14), pp. 2326-2328Fang, X.-H., Hu, M.-L., Huang, L.-L., Chai, L., Dai, N.-L., Li, J.-Y., Tashchilina, A.Y., Wang, C.-Y., Multiwatt octave-spanning supercontinuum generation in multicore photonic-crystal fiber (2012) Opt. Lett., 37 (12), pp. 2292-2294Modotto, D., Manili, G., Minoni, U., Wabnitz, S., De Angelis, C., Town, G., Tonello, A., Couderc, V., Ge-doped microstructured multicore fiber for customizable supercontinuum generation (2011) IEEE Photon. J., 3 (6), pp. 1149-1156Reichenbach, K.L., Xu, C., Numerical analysis of light propagation in image fibers or coherent fiber bundles (2007) Opt. Express, 15 (5), pp. 2151-2165Hirano, M., Future of transmission fiber (2011) IEEE Photon. J., 3 (2), pp. 316-319Zhu, B., Taunay, T.F., Yan, M.F., Fishteyn, M., Oulundsen, G., Vaidya, D., 70-Gb/s multicore multimode fiber transmissions for optical data links (2010) IEEE Photon. Technol. Lett., 22, pp. 1647-1649Zhu, B., Fini, J.M., Yan, M.F., Liu, X., Chandrasekhar, S., Taunay, T.F., Fishteyn, M., Dimarcello, F.V., High-capacity space-division-multiplexed DWDM transmissions using multicore fiber (2012) J. Lightwave Technol., 30 (4), pp. 486-492Lee, B.G., Kuchta, D.M., Doany, F.E., Schow, C.L., Pepeljugoski, P., Baks, C., Taunay, T.F., Li, N., End-to-End Multicore Multimode Fiber Optic Link Operating up to 120 Gb/s (2012) J. Lightwave Technol., 30 (6), pp. 886-892Zhu, B., Taunay, T.F., Yan, M.F., Fini, J.M., Fishteyn, M., Monberg, E.M., Dimarcello, F.V., Seven-core multicore fiber transmissions for passive optical network (2010) Opt. Express, 18 (11), pp. 11117-11122Rosinski, B., Chi, J.W.D., Grosso, P., Le Bihan, J., Multichannel transmission of a multicore fiber coupled with vertical-cavity surface-emitting lasers (1999) J. Lightwave Technol., 17 (5), pp. 807-810Taylor, D.M., Bennett, C.R., Shepherd, T.J., Michaille, L.F., Nielsen, M.D., Simonsen, H.R., Demonstration of multi-core photonic crystal fibre in an optical interconnect (2006) Electron. Lett., 42 (6), pp. 331-331Mangan, B.J., Knight, J.C., Birks, T.A., St. Russell, P.J., Greenaway, A.H., Experimental study of dualcore photonic crystal fibre (2000) Electron. Lett., 36 (16), pp. 1358-1359Mukasa, K., Imamura, K., Takahashi, M., Yagi, T., Development of novel fibers for telecoms application (2010) Opt. Fiber Technol., 16 (6), pp. 367-377Saitoh, K., Sato, Y., Koshiba, M., Coupling characteristics of dual-core photonic crystal fiber couplers (2003) Opt. Express, 11 (24), pp. 3188-3195Yan, Y., Toulouse, J., Nonlinear inter-core coupling in triple-core photonic crystal fibers (2009) Opt. Express, 17 (22), pp. 20272-20281Saitoh, F., Saitoh, K., Koshiba, M., A design method of a fiber-based mode multi/demultiplexer for modedivision multiplexing (2010) Opt. Express, 18 (5), pp. 4709-4716Yuan, L., Liu, Z., Yang, J., Guan, C., Bitapered fiber coupling characteristics between single-mode singlecore fiber and single-mode multicore fiber (2008) Appl. Opt., 47 (18), pp. 3307-3312Witkowska, A., Lai, K., Leon-Saval, S.G., Wadsworth, W.J., Birks, T.A., All-fiber anamorphic core-shape transitions (2006) Opt. Lett., 31 (18), pp. 2672-2674Lai, K., Leon-Saval, S.G., Witkowska, A., Wadsworth, W.J., Birks, T.A., Wavelength-independent all-fiber mode converters (2007) Opt. Lett., 32 (4), pp. 328-330Gerosa, R.M., Spadoti, D.H., Menezes, L.S., De Matos, C.J., In-fiber modal Mach-Zehnder interferometer based on the locally post-processed core of a photonic crystal fiber (2011) Opt. Express, 19 (4), pp. 3124-3129Gerosa, R.M., Biazoli, C.R., Cordeiro, C.M.B., De Matos, C.J.S., Post-processing multicore photonic crystal fibers for locally coupling selected core pairs (2011) CLEO: 2011 - Laser Applications to Photonic Applications, OSA Technical Digest (CD), , Optical Society of America, paper JWA39Gerosa, R.M., Spadoti, D.H., De Matos, C.J.S., Menezes, L.S., Franco, M.A., Efficient and short-range light coupling to index-matched liquid-filled hole in a solid-core photonic crystal fiber (2011) Opt. Express, 19 (24), pp. 24687-2469

Side Access To The Holes Of Photonic Crystal Fibers-new Sensing Possibilities

Side access to the holes of photonic crystal fibers is demonstrated with a novel technique. Liquid or gases to be sensed can, thus, be inserted via the fiber lateral while the tips are optically monitored. © 2006 Optical Society of America.Russell, P., Photonic crystal fibers (2003) Science, 299, pp. 358-362Knight, J.C., Photonic crystal fibres (2003) Nature, 424, pp. 847-851Monro, T.M., Richardson, D.J., Bennett, P.J., Developing holey fibers for evanescent field devices (1999) Electron. Lett., 35, pp. 1188-1189Hoo, Y.L., Jin, W., Ho, H.L., Wang, D.N., Windeler, R.S., Evanescent-wave gas sensing using microstructure fiber (2002) Opt. Eng., 41, pp. 8-9Jensen, J.B., Pedersen, L.H., Hoiby, P.E., Nielsen, L.B., Hansen, T.P., Folkenberg, J.R., Riishede, J., Bjarklev, A., Photonic crystal fiber based evanescent-wave sensor for detection of biomolecules in aqueous solutions (2004) Opt. Lett., 29, pp. 1974-1976Fini, J.M., Microstructure fibres for optical sensing in gases and liquids (2004) Meas. Sci. Technol., 15, pp. 1120-1128Birks, T.A., Bird, D.M., Hedley, T.D., Pottage, J.M., Russell, P.S., Scaling laws and vector effects in bandgap guiding fibers (2004) Opt. Express, 12, pp. 69-74Cox, F.M., Argyros, A., Large, M.C.J., Liquid-filled hollow core microstructured polymer optical fiber (2006) Opt. Express, 14, pp. 4135-4140Lehmann, H., Brückner, S., Kobelke, J., Schwotzer, G., Schuster, K., Willsch, R., Toward photonic crystal fiber based distributed chemosensors (2005) 17th International Conference on Optical Fibre Sensors, SPIE, 5855, pp. 419-42

Generation Of Polarizing Sections In Highly Birefringent Photonic Crystal Fibers Via Post-processing

The structure of a commercial highly birefringent PCF was locally tapered to create a polarizing section. A polarization-depended loss of at least 32.2 dB over a 1-cm length was induced in the 1550-nm region. © OSA 2013.Saitoh, K., Koshiba, M., IEEE Photonics Technology Letters (2003), 15 (10)Zhang, F., Zhang, M., Liu, X., Ye, P., Journal of Lightwave Technology (2007), 25 (5)Espinel, A.V.Y., Franco, M.A.R., Cordeiro, C.M.B., Journal of Lightwave Technology (2011), 19 (16)Sodré Jr., A.C., Nascimento Jr., A.R., Franco, M.A.R., Oliveira, I., Serrão, V.A., Fragnito, H.L., Optical Fiber Technology (2012), 18, pp. 462-469Qian, W., Zhao, C.L., Wang, Y., Chan, C.C., Liu, S., Jin, W., Optics Letters (2011), 36 (16