| dc.description.abstract |
The conventional fiber communication band at 1.55 µm is approaching its capacity limit due to the growing demand for high-speed and large-volume data transmission. In re- sponse, the 2 µm waveband is emerging as a promising candidate for next-generation communication systems, offering higher capacity and lower transmission loss. In align- ment with this technological shift, we present an optically engineered metasurface tai- lored for this waveband, suitable for applications such as fiber coupling and lensing. The proposed device exhibits polarization insensitivity and dynamic tunability between its transmissive (ON) and reflective (OFF) states. To enable this tunability, we incorpo- rate a novel phase change material, In3SbTe2 (IST), which features fast, reversible, and non-volatile transitions between its metallic and insulating phases. Electrical control is achieved by integrating indium tin oxide (ITO) as a micro-heating element, which modulates the optical properties of IST, thereby enhancing the device’s applicability in point-of-care systems. Utilizing the Finite-Difference-Time-Domain (FDTD) method, we demonstrate a modulation depth of 90%, a high focusing efficiency of 76%, and an ON-OFF switching ratio of 26 dB. The use of multiple thin IST layers ensures uni- form and energy-efficient switching, with a low energy requirement of 232.98 nJ/µm2. With its outstanding performance at the 2 µm communication band and dynamic mul- tifunctional capabilities, the proposed metasurface stands poised to transform future telecommunication technologies and broader optical systems. |
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