Biomedical subjects

Chiyan Luo

Publications and source records attributed to Chiyan Luo.

5 recordsLinked to original sources

PubMed2006

Doppler radiation emitted by an oscillating dipole moving inside a photonic band-gap crystal.

We study the radiation emitted by an oscillating dipole moving with a constant velocity in a photonic crystal, and analyze the effects that arise in the presence of a photonic band gap. It is demonstrated through numerical simulations that the radiation strength may be enhanced or inhibited according to the photonic band structure, and anomalous effects in the sign and magnitude of the Doppler shifts are possible, both outside and inside the gap. We suggest that this effect could be used to identify the physical origin of the backward waves in recent metamaterials.

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PubMed2004

Thermal radiation from photonic crystals: a direct calculation.

A classical simulation of equilibrium thermal emissivity from dispersive, lossy photonic crystals is presented. Normal emission results consistent with those assuming Kirchoff's law are obtained; i.e., a photonic crystal does not emit more than what a blackbody does. Significant enhancement, however, can be achieved over the radiation intensity from a uniform slab, indicating the potential usefulness of photonic crystals in incandescent lighting and thermal photovoltaic applications.

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PubMed2004

Superprism effect based on phase velocities.

The superprism effect has been studied in the past by use of the anomalous group velocities of optical waves in photonic crystals. We suggest the possibility of realizing agile beam steering based on purely phase-velocity effects. We present designs of photonic crystal prisms that might make experimental observation of this effect possible.

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PubMed2003

Nonlinear photonic crystal microdevices for optical integration.

A four-port nonlinear photonic crystal system is discussed that exhibits optical bistability with negligible backscattering to the inputs, making it particularly suitable for integration with other active devices on the same chip. Devices based on this system can be made to be small [O(lambda3)] in volume, have a nearly instantaneous response, and consume only a few milliwatts of power. Among many possible applications, we focus on an all-optical transistor and integrated optical isolation.

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PubMed2003

Cerenkov radiation in photonic crystals.

In a conventional material, the coherent Cerenkov radiation due to a moving charged particle is associated with a velocity threshold, a forward-pointing radiation cone, and a forward direction of emission. We describe different behavior for the Cerenkov radiation in a photonic crystal. In particular, this radiation is intrinsically coupled with transition radiation and is observable without any threshold. Within one particle-velocity range, we found a radiation pattern with a backward-pointing radiation cone. In another velocity range, backward-propagating Cerenkov radiation can be expected. Potential applications include velocity-sensitive particle detection and radiation generation at selectable frequencies.

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