Wyniki wyszukiwania - BazTech

Ograniczanie wyników

2 Optica Applicata

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: photonic bandgaps

Sortuj według:

Ogranicz wyniki do:

Further enhancement of light extraction efficiency of light-emitting diode with Ag film grown on photonic crystals

Chen J., Wang Q., Li H.

Optica Applicata

2011

Vol. 41, nr 1

51--61

Photonic bandgap of photonic crystals (PCs) and the effect of grating diffraction can be used to improve the extraction efficiency of the light from a light-emitting diode (LED). The transmission of light at certain wavelength through periodic sub-wavelength hole arrays in metal films is extraordinary, because the surface plasmon acts effectively. In this letter, PCs with the square lattice of cylinder unit cells are placed in GaN layer of GaN-based blue LED, and the silver film is plated on PCs. The finite-difference time-domain (FDTD) method is used to investigate the optical transmission; the results show that the extraction efficiency of the PC-assisted LED (PC-LED) is enhanced when the silver film is plated on the PCs under certain conditions. Finally, we use the surface plasmon dispersion relation to analyze the mechanism of antireflection.

Optimization of two- dimensional photonic crystal waveguides for TE and TM polarizations

Danaie M., Attari A. R., Mirsalehi M. M., Naseh S.

Optica Applicata

2008

Vol. 38, nr 4

643-655

In this paper, we optimize the geometries of some 2D photonic crystal waveguides to increase their single-mode bandwidths for TE and TM polarizations. Using the Plane Wave Expansion (PWE) method combined with optimization algorithm, we find the local maxima as well as the global maximum. A photonic crystal waveguide geometry is proposed which has a single-mode normalized bandwidth of 41% for TM polarization. This value is about 7% greater than the corresponding value for the commonly used square lattice of dielectric rods in which a row is removed. Also, some waveguide geometries are proposed for TE polarization and it is shown that one of these geometries can provide a single-mode bandwidth of 39%, while the widest bandwidth reported so far for the TE case is 21%. The dielectric material used for both cases is GaAs with a dielectric constant of 11.4.