Numerical And Experimental Studies For A High Pressure Photonic Crystal Fiber Based Sensor

We report a study of using photonic crystal fibers (PCFs) for high pressure applications. An opto-mechanical analysis was realized in regular PCFs and suspended-core microstructured optical fibers for different fiber geometrical parameters. It was found that the pressure sensitivity is highly dependent on the fiber structure. It was also experimentally shown that even small core PCFs with high air filling fraction can deal with pressures as high as 500 bar (7350 psi) without any noticeable problem. © American Institute of Physics.1055133136de Matos, C.J.S., (2008) CLEO conferenceR.E.P. de Oliveira, submitted to WSOF2008 AIP Proceedings (2008)Cordeiro, C.M.B., (2007) Optics Letters, 32, pp. 3324-3326Szpulak, M., Martynkien, T., Urbanczyk, W., (2004) Appl. Optics, 43, pp. 4739-4744MacPherson, W.N., (2005) Journal Light, 23, pp. 1227-1231. , TechnZhou, J., (2006) OFC'06, WI2Kosolapov, A.F., (2006) Inorganic Materials, 43, pp. 310-31

Refractometric Sensor Based On All-fiber Coaxial Michelson And Mach-zehnder Interferometers For Ethanol Detection In Fuel

A refractometric sensor based on mechanically induced interferometers formed with long period gratings is reported. It is also shown two different setups based on a Michelson and Mach-Zender interferometer and its application to measure ethanol concentration in gasoline.2741OSA,SPIE,ICO,JPCS,Quantel,CIOAshish, M.V., Lemaire, P.J., Judkins, J.B., Bhatia, V., Turan, E., Sipe, J.E., (1996) J. Lightwave Tech., 14 (1)James, S.W., Tatam, R.P., (2003) Meas. Sci. Technol., 14, pp. R49-R61Chomát, M., Berková, D., Matejec, V., Kasík, I., Kanka, J., Slavík, R., Jancárek, A., Bittner, P., (2006) Mater. Sci. Eng. C, 26, pp. 457-461Petrovic, J.S., Dobb, H., Mezentsev, V.K., Kyriacos, K., Webb, D.J., Bennion, I., (2007) J. Lightwave Tech., 25 (5)Chan, H.M., Fares, A., Tomov, I.V., Lee, H.P., (2008) IEEE Photon. Technol. Lett., 20 (8)Dürr, F., Rego, G., Marques, P.V.S., Semjonov, S.L., Dianov, E.M., Limberger, H.G., Salathé, R.P., (2005) J. Lightwave Tech., 23 (11)Smietana, M., Bock, W.J., Mikulic, P., (2010) Meas. Sci. Technol., 21Savin, S., Digonnet, M.J.F., Kino, G.S., Shaw, H.J., (2000) Optic. Lett., 25 (10)Xiaojun, Z., Chen, C., Zhang, Z., Qin, Z., Liu, Y., (2009) 14th OptoElectronics and Communications Conf. OECC, , art. No 5218070Swart, P.L., (2004) Meas. Sci. Technol., 15, pp. 1576-1580Barrios, P., Sáez, R.D., Rodríguez, A., Cruz, J.L., Díez, A., Andrés, M.V., (2009) J. Sensors, , ID 815409Liu, Y., Williams, J.A.R., Zhang, L., Bennion, I., (1999) Opt. Commun., 164, pp. 27-31Wei, T., Lan, X., Xiao, H., (2009) IEEE Photon. Technol. Lett., 21 (10), pp. 669-671Young-Geun, H., Lee, B.H., Won-Taek, H., Paek, U.C., Chung, Y., (2001) Meas. Sci. Technol., 12, pp. 778-781Falate, R., Kamikawachi, R.C., Fabris, J.L., Müller, M., Kalinowski, H.J., Ferri, F.A.S., Czelusniak, L.K., (2003) Proc. Microwave and Optoelectronics Conference (20-23 Sept 2003), 2, pp. 907-91

Existence of the Wigner function with correct marginal distributions along tilted lines on a lattice

In order to determine the Wigner function uniquely, we introduce a new condition which ensures that the Wigner function has correct marginal distributions along tilted lines. For a system in $N$ dimensional Hilbert space, whose "phase space" is a lattice with $N^2$ sites, we get different results depending on whether $N$ is odd or even. Under the new condition, the Wigner function is determined if $N$ is an odd number, but it does not exist if $N$ is even.Comment: 18 page

Faithful remote state preparation using finite classical bits and a non-maximally entangled state

We present many ensembles of states that can be remotely prepared by using minimum classical bits from Alice to Bob and their previously shared entangled state and prove that we have found all the ensembles in two-dimensional case. Furthermore we show that any pure quantum state can be remotely and faithfully prepared by using finite classical bits from Alice to Bob and their previously shared nonmaximally entangled state though no faithful quantum teleportation protocols can be achieved by using a nonmaximally entangled state.Comment: 6 page

Wigner Functions on a Lattice

The Wigner functions on the one dimensional lattice are studied. Contrary to the previous claim in literature, Wigner functions exist on the lattice with any number of sites, whether it is even or odd. There are infinitely many solutions satisfying the conditions which reasonable Wigner functions should respect. After presenting a heuristic method to obtain Wigner functions, we give the general form of the solutions. Quantum mechanical expectation values in terms of Wigner functions are also discussed.Comment: 11 pages, no figures, REVTE

Teleparallel Versions of Friedmann and Lewis-Papapetrou Spacetimes

This paper is devoted to investigate the teleparallel versions of the Friedmann models as well as the Lewis-Papapetrou solution. We obtain the tetrad and the torsion fields for both the spacetimes. It is shown that the axial-vector vanishes for the Friedmann models. We discuss the different possibilities of the axial-vector depending on the arbitrary functions $\omega$ and $\psi$ in the Lewis-Papapetrou metric. The vector related with spin has also been evaluated.Comment: 13 pages, accepted for publication in GR

On the choice of heavy baryon currents in the relativistic three-quark model

We test the sensitivity of bottom baryon observables with regard to the choice of the interpolating three-quark currents within the relativistic three-quark model. We have found that the semileptonic decay rates are clearly affected by the choice of currents, whereas the asymmetry parameters show only a very weak dependence on the choice of current.Comment: revtex, 9 page

Scanning microscopies of superconductors at very low temperatures

We discuss basics of scanning tunneling microscopy and spectroscopy (STM/S) of the superconducting state with normal and superconducting tips. We present a new method to measure the local variations in the Andreev reflection amplitude between a superconducting tip and the sample. This method is termed Scanning Andreev Reflection Spectroscopy (SAS). We also briefly discuss vortex imaging with STM/S under an applied current through the sample, and show the vortex lattice as a function of the angle between the magnetic field and sample's surface

Teleparallel Version of the Levi-Civita Vacuum Solutions and their Energy Contents

In this paper, we find the teleparallel version of the Levi-Civita metric and obtain tetrad and the torsion fields. The tensor, vector and the axial-vector parts of the torsion tensor are evaluated. It is found that the vector part lies along the radial direction only while the axial-vector vanishes everywhere because the metric is diagonal. Further, we use the teleparallel version of M$\ddot{o}$ller, Einstein, Landau-Lifshitz and Bergmann-Thomson prescriptions to find the energy-momentum distribution of this metric and compare the results with those already found in General Relativity. It is worth mentioning here that momentum is constant in both the theories for all the prescriptions. The energy in teleparallel theory is equal to the corresponding energy in GR only in M$\ddot{o}$ller prescription for the remaining prescriptions, the energy do not agree in both theories. We also conclude that M$\ddot{o}$ller's energy-momentum distribution is independent of the coupling constant $\lambda$ in the teleparallel theory.Comment: 15 pages, accepted for publication in Canadian J. Physic

Resolution of dark matter problem in f(T) gravity

In this paper, we attempt to resolve the dark matter problem in f(T) gravity. Specifically, from our model we successfully obtain the flat rotation curves of galaxies containing dark matter. Further, we obtain the density profile of dark matter in galaxies. Comparison of our analytical results shows that our torsion-based toy model for dark matter is in good agreement with empirical data-based models. It shows that we can address the dark matter as an effect of torsion of the space.Comment: 14 pages, 3 figure