Exciton polaritons in one-dimensional metal-semiconductor photonic crystals.
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.
Márquez-Islas
R
R
Facultad de Ciencias Físico Matemáticas, Universidad Autónoma de Puebla, Apdo. Post. 1152, Puebla, Pue. 72000, México.
Flores-Desirena
B
B
Pérez-Rodríguez
F
F