Wideband waveguide loading impedance matching on the basis of photonic crystals with nanometer metal layers

We investigate theoretically the coupling of exciton with light in a one-dimensional photonic crystal. The unit cell of the crystal consists of two alternating layers, namely a metallic layer and a semiconductor one. The frequency-dependent dielectric function of the metal is described by the Drude model, whereas for the semiconductor we use a nonlocal excitonic dielectric function. The polariton dispersion for s-polarized modes in the metal-semiconductor photonic crystal is compared with that for a dielectric-semiconductor photonic crystal. Because of the metal layers, a low-frequency gap appears in the photonic band structure. The presence of the semiconductor gives rise to photonic bands associated with the coupling of light with size-quantized excitón states. At frequencies above the longitudinal exciton frequency, the photonic band structure exhibits anticrossing phenomena produced by the upper exciton–polariton mode and size-quantized excitons. It is found that the anticrossing phenomena in the metal-semiconductor photonic crystal occur at higher frequencies in comparison with the dielectric-semiconductor case.

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Wideband Waveguide Matched Loads Based on Photonic Crystals with Nanometer Metal Layers

2008 38th European Microwave Conference ◽

10.1109/eumc.2008.4751494 ◽

2008 ◽

Cited By ~ 1

Author(s):

Dmitry A. Usanov ◽

Alexander V. Skripal ◽

Anton V. Abramov ◽

Anton S. Bogolubov ◽

Vladimir S. Skvortsov ◽

...

Keyword(s):

Photonic Crystals ◽

Metal Layers

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STM of freeze-fracture replicas: Problems and promises

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100146187 ◽

1993 ◽

Vol 51 ◽

pp. 68-69

Author(s):

J. T. Woodward ◽

J. A. N. Zasadzinski

Keyword(s):

Scanning Tunneling Microscope ◽

Organic Materials ◽

Freeze Fracture ◽

Atomic Resolution ◽

Scanning Tunneling ◽

Tunneling Microscope ◽

Molecular Scale ◽

Organic Surfaces ◽

Metal Layers ◽

Conductive Surfaces

The Scanning Tunneling Microscope (STM) offers exciting new ways of imaging surfaces of biological or organic materials with resolution to the sub-molecular scale. Rigid, conductive surfaces can readily be imaged with the STM with atomic resolution. Unfortunately, organic surfaces are neither sufficiently conductive or rigid enough to be examined directly with the STM. At present, nonconductive surfaces can be examined in two ways: 1) Using the AFM, which measures the deflection of a weak spring as it is dragged across the surface, or 2) coating or replicating non-conductive surfaces with metal layers so as to make them conductive, then imaging with the STM. However, we have found that the conventional freeze-fracture technique, while extremely useful for imaging bulk organic materials with STM, must be modified considerably for optimal use in the STM.

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