Continuously tunable intensity modulators with large switching contrasts using liquid crystal elastomer films that are deposited with terahertz metamaterials
Chiang, Wei-Fan, Harry Miyosi Silalahi, Yu-Chih Chiang, Mi-Chia Hsu, Yan-Song Zhang, Jui-Hsiang Liu, Yanlei Yu, Chia-Rong Lee, and Chia-Yi Huang. “Continuously tunable intensity modulators with large switching contrasts using liquid crystal elastomer films that are deposited with terahertz metamaterials.” Optics Express 28, no. 19 (2020): 27676-27687.
A liquid crystal elastomer (LCE) film is successfully deposited with a terahertz metamaterial using thermal evaporation via a programmed electronic shutter and high-efficiency cooling system. The transmittance of the metamaterial at its resonance frequency is monotonically increased from 0.0036 to 1.0 as a pump beam bends the LCE film, so the metamaterial has a large switching contrast of 277 at the frequency. The monotonic increase in the resonance transmittance arises from the constant resonance frequency of the metamaterial at the transmittance modulation and depicts that the metamaterial-deposited LCE film can continuously tune the transmitted intensity of a terahertz beam. The metamaterial-deposited LCE film has potential in developing continuously tunable intensity modulators with large switching contrasts for the application of terahertz imaging and terahertz communication. Therefore, the thermal evaporation expands the application of metamaterials and improves their optical properties.
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