Reinforcement of optical wave transmission by using two cap-layers in a multilayer structure containing nano-scale blocks

摘要

In a layered structure containing nano-scale layers, we have presented the possibility of increasing the wave transmission in the visible region by adding the top and bottom cap layers. It is found that, the structure containing both the top and bottom cap layers (S-3) yields larger transmittance than the structures S-1 without any cap or S-2 just with one cap layer. The maximum transmittance in the visible range can be increased from 33 to 67. In addition, for the TE mode (the TM mode) the maximum value of transmission in the S-1 and S-2 structures occurs at angles close to normal incidence while in the S-3 multilayer it happens around 1 rad, that is, the behavior of the TE mode is the opposite of the TM mode. Also, when the incident angle varies, the band edges experience a blue shift. The amount of TE shift is more pronounced than TM one.