Numerical study of tunable enhanced chirality in multilayer stack achiral phase-change metamaterials

作者：Cao, Tun^*; Li, Yang; Wei, Chen-Wei; Qiu, Yi-Mei

来源：Optics Express, 2017, 25(9): 9911-9925.

DOI：10.1364/OE.25.009911

• CIRCULAR-DICHROISM
• ASYMMETRIC TRANSMISSION
• PERFECT ABSORBER
• POLARIZED WAVES
• LIGHT
• SPECTROSCOPY
• ABSORPTION
• RESONANCE
• FILMS
• INDEX

We numerically demonstrate a multiband circular dichroism (CD) by tilting achiral metamaterials (MMs) composed of an elliptical nanoholes array (ENA) penetrating through metal/phase-change material (PCM) /metal multilayer stack, with respect to the incident light. The CD spectrum can be actively tuned across a wide range from the near-infrared (NIR) to mid-infrared (MIR) regime by transiting the state of the PCM (Ge2Sb2Te5) from amorphous to crystalline. Thus, it can switch on/off a multiband chiroptical response in the infrared region. Our simulation also elucidates that the achiral multilayer stack MMs, which have strong magnetic resonances, can enhance the optical chirality inside the elliptical apertures for both amorphous and crystalline states. The switching of the enhanced chirality may pave the way to manipulate electromagnetic waves, such as tunable circular polarizers, chiroptical spectroscopy, and chiral biosensors.

• 出版日期2017-5-1
• 单位大连理工大学