The enhanced infrared absorption of quantum well infrared photodetector based on a hybrid structure of periodic gold stripes overlaid with a gold film

The hybrid structure of periodic gold stripes overlaid with a gold film is proposed to enhance the infrared absorption of quantum well infrared photodetector. The reflection spectra and the field distributions are numerically calculated by a finite difference time-domain method. The results show that the electric field component perpendicular to the quantum well is strongly enhanced when the plasmonic resonance of the hybrid structure occurs at the operation wavelength of the quantum well infrared photodetector. The effect of the structural parameters on the plasmonic resonant wavelength is discussed, which indicates that the localized surface plasmon as well as surface plasmon polariton plays a role in the light coupling with the hybrid structure. A high coupling efficiency can be obtained with the optimized structural parameters. In addition, the performance of the hybrid structure at the tilted incidence is investigated.