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Utilising radio OAM to study space plasma vorticity The LOIS concept and IBM software

Utilising radio OAM to study space plasma vorticity The LOIS concept and IBM software. Bo Thidé Swedish Institute of Space Physics , IRF, and Uppsala University, Uppsala, Sweden LOIS Space Centre, Växjö, Sweden with contributions from the LOIS OAM/radio topology collaboration

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Utilising radio OAM to study space plasma vorticity The LOIS concept and IBM software

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  1. Utilising radio OAM to studyspace plasma vorticityThe LOIS concept and IBM software Bo Thidé Swedish Institute of Space Physics, IRF, and Uppsala University, Uppsala, Sweden LOIS Space Centre, Växjö, Sweden with contributions from the LOIS OAM/radio topologycollaboration J. Bergman, S. Mohammadi, T. Leyser, E. Nordblad (Uppsala), L. Daldorff, (FMI, Helsinki), R. Karlsson (Graz), T. Carozzi (Glasgow), H. Lundstedt (Lund), W. Löwe, W. Baan, M. Milrad (Växjö), M. Fredriksson, R. Gustavsson, N. Ibragimov, R. Khamitova. C. Svahnberg (BTH, Karlskrona), H. Then (Oldenburg), T. Mendonca (Lisbon), Ya. N. Istomin (LebedevInstitute, Moscow), E. Weibust, B. Sjökvist (IBM Sweden), B. Elmegreen, L. Amini, A. Biem, D. Turaga, and O. Verscheure (IBM Research, NY)

  2. Early LOFAR proposals – Birth of the LOIS project

  3. LOIS idea: Optimize LOFAR for spaceweather, solar physics, ionosphericturbulence and calibration... Download from www.lois-space.net

  4. Fundamental question: How much physical information is embedded in EM radiation? Start from the beginning: the microscopic Maxwell-Lorentz equations Symmetric under inhomogeneous Lorentz transformations. The concomitant Lie group is the 10-dimensional Poincaré group P(10). According to Noether’s theorem there therefore exist 10 conserved EM quantities. In fact there exist 23 exact continuous symmetries/conserved quantities (in vacuo), plus an as yet unknown number of approximate, conservation laws [Ibragimov, 2008].

  5. Conserved quantities in EM fields and matter (1) Homogeneity in time => conservation of system energy (Poynting’s theorem): Homogeneity in space => conservation of system linear momentum (gives, e.g., rise to EM Doppler shift):

  6. Conserved quantities in EM fields an matter (2) Invariance under proper Lorentz transformations => conservation of system centre of energy: Isotropy in space => conservation of system angular momentum (gives rise to azimuthal Doppler shift): Foundation of ‘angular momentum radio’ and vorticity probing radio and radar methods.

  7. Total radiated EM field angular momentum For radiation beams in free space, EM field angular momentum Jem can be separated into two parts [Jackson, 1998; Thidé, 2009]: For each single Fourier mode in real-valued representation [van Enk & Nienhuis, 1992]: The first part is the EM spin angular momentum (SAM) Sem, a.k.a. wave polarisation, and the second part is the EM orbital angular momentum (OAM)Lem. NB: In general, both EM linear momentum pem, and EM angular momentum Jem = Lem+ Semare radiated all the way out to the far zone!

  8. That far-zone POAM is generated by near-zone longitudinal E fields is well known since 1914

  9. Micromechanical action of laser light carrying SAM and OAM Particles of sizes 1–3 μm irradiated by SAM/OAM laser beams Orbital angular momentum l = 8 Spin angular momentum s = 1

  10. EM beams on same frequencybutdifferent OAM are orthogonal and donot interfere with eachother! M. J. Padgett, J. Leach et al., U. Glasgow, UK; Royal Society l=+3 l=+1 Spiraling Poynting/OAM vectors carry a lot of information! The Jones matrix goes from 2×2 to 2(j+1)×2(j+1), j=s+l . l= -4

  11. Topological degrees of freedom have revolutionised wireless communications

  12. First observation of angularmomentum in ionospheric radio emissions,Tromsø, 1983 Bo Thidé. Stimulated Electromagnetic Emission and nonlinear wave-wave interactions in ionospheric heating experiments. In M. Q. Tran and M. L. Sawley, editors, Proceedings, Contributed Papers, International Conference on Plasma Physics, volume I, page 131, Lausanne, Switzerland, 27 June-3 July 1984. Centre de Recherche en Physique des Plasmas, EcolePolytechnique Federal de Lausanne, CRPP-EPFL. Circular, (nearly) O-mode pumping O mode SEE X mode SEE

  13. Imparting OAM onto an EM beam (laser, mm wave) with the help of a spiral plate or hologram

  14. Observations at 94 GHz of angular momentum induced azimuthal (rotational ) Doppler shift

  15. Use of photonorbitalangularmomentum (POAM) has come to the fore in astronomy and astrophysics

  16. Europe is leading the way

  17. Deep space radar requirements Courtesy Paul Rodrigues

  18. OAM spectrum probing (spiral imaging) – a new scatter radar diagnostic Recent digital spiral imaging experiments (Ll. Torner et al., Opt. Express, 13, 873–881, 2005; Molina-Terriza et al., J. Eur. Opt. Soc., Rapid Publ., 2, 07014, 2007) have demonstrated that probing with OAM gives a wealth of new information about the object under study. The stimulus…

  19. Spiral (OAM) spectrum imaging results …and its response

  20. Linear transfer of OAM radio ↔ plasma PRL, in press

  21. Nonlinear transfer of OAM radio <-> plasma Brillouin = ionline Raman = plasma line

  22. First unambiguous observation of StimulatedBrillouinScattering in the ionosphere

  23. First OAM/vorticity radio injection experiment in the ionospheric plasma (HAARP, Alaska, 27 Feb, 2008)

  24. Field vector sensing means total configurability Very good solar radio coronagraph!

  25. Radio beam topology degrees of freedomLinear momentum (Poynting) flux and E vs. OAM Mohammadiet al., IEEE Trans. Ant. Prop., in press, 2009

  26. Radio beam topology degrees of freedomLeft: Conventional linear momentum (Poynting) flux and ERight: Orbital angular momentum flux

  27. LOIS has measured the photon spin currentV in ionospheric radio signals since 2003

  28. LOIS resources 2003–today (total ~ 2.5 MEur) Computer cluster (two SUR grants from IBM), currently in Uppsala. To be moved to Ronneby The control room at the LOIS Test Station Risinge/Växjö. Radio Sweden’s 500 kW transmitter located about 100 km south of the Växjö LOIS test station and 100 km south-west of the Ronneby prototype station site. Will be used for space radar tests. 9m×8m×6m antenna chamber, Ångström Lab, Uppsala Magnetometer, LOIS Test Station, Risinge/Växjö

  29. New LOIS prototype site at Angelskog, RonnebyLeft photos taken 21 December, 2007, at 14:00 local time. Right photo from eniro.se

  30. LOIS prototype station under construction in RonnebyTo be augmented by two outer, concentric rings, with 16 and 32 radio units, respectively, for a total of 56 units with three dipoles each (funding permitting)

  31. Use three orthogonal electric and magnetic antennas to sample the entire EM field vector New generation LOIS radio sensors, to be first used at EISCAT, autumn 2009

  32. 3D vector antenna allows entirely new radio Better SNR, polarisation in real time, DOA,… Click on pictures for animation! Real data from a real, live outdoor vector receiver at Ångström Lab in Uppsala. On line since 2003. Instantaneous wave polarisation from one single vector antenna Vector coherency gives superior SNR relative to conventional scalar intensity

  33. LOIS prototype station sensitivity 48 tripoles=144 dipoles

  34. 2D LOFAR/SKA-type interferometers may exhibit polarisation aberration. 3D interferometers do not Swedish LOFAR Science Meeting, Stockholm, 15 January, 2009

  35. IBM InfoSphere Streams ideal for LOIS radio data

  36. IBM InfoSphere Streams partly developedfor LOIS

  37. InfoSphere Streams (System S) program for a distributed network of LOIS radio sensors

  38. LOIS software developed in collaboration with IBM

  39. IBM’s latest major data stream software package developed for LOIS radio data

  40. LOIS has given rise to articles in the press

  41. LOIS /LOFAR on Discovery Channel?

  42. Thank you for your attention ....there may be more things in heaven and earth than even Maxwell had dreamt of …

  43. EM equivalent of fluid vorticity

  44. Phase singularities (dislocations) are to be expectedin radio beams propagating through space

  45. Standard textbooks show that classical EM angular momentum is indeed radiated all the way to infinity

  46. Pack EM beams with much more data by utilising more topological degrees of freedom

  47. Single photons can carry both spin angular momentum Sand orbital angular momentum L!

  48. Hyperentangled SAM and OAM photon states break the linear-optics channel capacity threshold

  49. Shannon’s law revisited

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