Tunable Narrow Band Plasmonic Absorber Based on Liquid Crystal and Gold Squares

In this paper, the absorption of gold square arrays with different sizes is investigated in near infrared regime. The gold squares are dispersed in 5CB type of liquid crystal to make the proposed absorber tunable. It is shown that the size of gold squares plays a great role in the absorption behavior of the proposed absorber. The obtained absorptions by two different sizes of gold squares are narrow band which are more than 95%. As three different gold squares are utilized in the structure, three more than 85% absorption peaks are created. The tunability of the proposed structures is about 30 nm as the optical angle varies between 0o and 90o by the applied voltage.