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Surface polaritons in layered semiconductor structures M. Duracz, A. Rusina. Saint-Petersburg State Polytechnical University, Saint-Petersburg, Russia.

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Presentation on theme: "Surface polaritons in layered semiconductor structures M. Duracz, A. Rusina. Saint-Petersburg State Polytechnical University, Saint-Petersburg, Russia."— Presentation transcript:

1 Surface polaritons in layered semiconductor structures M. Duracz, A. Rusina. Saint-Petersburg State Polytechnical University, Saint-Petersburg, Russia.

2 Surface polariton A polariton is an electromagnetic wave that is linearly coupled to an electric or magnetic dipole active elementary excitation in a condensed medium, i.e. it is a photon coupled to a plasmon, phonon, exciton, etc. A surface polariton is a polariton whose associated electromagnetic field is localized at the surface of the medium.

3 Contents   Brief review of the surface polaritons   Surface polaritons at interface   Experiments with surface polaritons   Surface polaritons in a layer

4 Surface electromagnetic waves Zenneck modes radio frequency surface electromagnetic waves that occur at the surface of absorbent medium Brewster modes damping brings ‘Brewster case’ rays into two exponentially decaying away from the interface waves Fano modes the only surface normal modes that exist at the surface in absence of damping

5 Negative dielectric function occurs in conductors in insulators the nearly free electron picture of simple metals gives surface polaritons (called surface plasmons) can propagate in the vicinity of natural frequency of the medium is the plasma frequency condition for surface polariton propagation is realized in dielectrics almost always just above an absorption line (surface phonon, exciton polaritons)

6 Planar wave hits the interface incidence of p-polarized wave electric fields

7 Boundary conditions for magnetic field for electric field after the transformation or

8 Fresnel formulae equations for reflected and refracted waves if there’s no incident wave and Fano, 1941

9 Surface polaritons condition for field to exist together with definitions of lead to and restrictions on permittivities and for wave to propagate along the interfaceso

10 Localized field wave vector magnetic field distribution

11 Dispersion curve SP at the media with the resonance

12 Exciting of SP on a line grating conservation law Beaglehole, 1969

13 Prism coupling. Otto geometry attenuated total reflection Otto, 1968

14 Kretschmann geometry attenuated total reflection Kretschmann, 1971

15 Two-prism method coupling-decoupling of light & surface waves couplingdecoupling

16 Edge coupling technique surface polariton frustration on the edge inverse process diffraction pattern Agranovich, 1975 Chabal, Sievers, 1978

17 From edge to edge “jumping” frustrated SP transforms into another one Zhizhin, 1982

18 Insertion of second interface alteration of the field

19 Double-interface polaritons field associated with a new mode

20 Characteristic equation using Fresnel formulae these equations are consistent if Maradudin, 1981

21 Two branches of the modes characteristic equation for positiveresolves only if this means left side of the equation is positive or null so there’s two eventualities are both positive or negative

22 “Slow” double-interface modes in case of negative brackets characteristic equation transforms to assuming this equation is solvable if

23 “Slow” modes’ field one-interface limit asymptotic behaviour for small

24 “Fast” double-interface modes in case of positive brackets that is solvable if characteristic equation transforms to

25 “Fast” modes’ field. Typical case one-interface limit

26 “Fast” modes’ field. Unusual case non-typical range asymptotic behaviour for small

27 transparencydissipation Influence of damping changes of dielectric function - damping constant transparency of the medium criterion

28 Dispersion curves “slow” & “fast” double-interface polaritons dissipation SM FM

29 Frequency region shift the thickness of the slab varies SM FM dissipation

30 Excitonic polaritons in lasers from volume to surface polaritons Ledentsov, 1998

31 Thank you!


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