Phase change materials, such as Ge₂Sb₂Te₅ (GST), have been extensively explored to realize tunable radiation. However, not too much attention was paid to tunable transmission. In this paper, we propose a tri-layer GST-based planar structure for tuning transmission. It is found that the transmission can be significantly tuned during the phase transition of GST and the difference in transmission can be beyond 0.9 between the amorphous phase and crystalline phase of GST. The physical mechanism is that the Fabry-Perot (FP) resonance can be formed at the amorphous phase of GST, while that cannot be formed at the crystalline phase of GST. Besides, the proposed structure remains excellent performance when the angle of incidence is smaller than 30° under TM polarization. We believe the tunable transmission realized in this work is promising in the application of optical switch and asymmetric transmission.

相变材料，例如Ge ₂ Sb ₂ Te ₅（GST）已被广泛探索以实现可调辐射。但是，对可调传输并没有太多的关注。在本文中，我们提出了一种基于三层GST的平面结构，用于调谐传输。发现在GST的相变期间可以显着地调节透射率，并且在GST的非晶相和结晶相之间的透射差可以超过0.9。物理机制是法布里-珀罗（FP）共振可以在GST的非晶相形成，而不能在GST的结晶相形成。此外，当在TM偏振下入射角小于30°时，所提出的结构仍保持优异的性能。