小像元量子阱FPA抗光学串音的FDTD仿真

FDTD simulation of the performance on Anti-optical crosstalk of Small Pixel Quantum well Focal Plane Array

摘要:

小尺寸量子阱光栅耦合(grating coupling)结构在工艺上难以制备，反射耦合（reflective coupling）结构较为容易，为探究反射耦合结构是否可以在小尺寸范围内替代光栅耦合结构，本文使用FDTD电磁场仿真软件MEEP对光栅耦合结构和反射结构的小像元GaAs/AlGaAs量子阱红外焦平面阵列在入射光到达衍射极限时的串音问题进行了仿真，验证了在逼近衍射极限时，采用全内反射结构的FPA在5-6.5μm和8.5-10μm之间的抗串音效果强于光栅耦合结构，而在6.5-8.5μm和10-12μm之间，光栅耦合结构的抗串音效果更强，在12-15μm的范围内，两种结构的抗串音能力相当。并仿真了全内反射结构的反射角度、刻蚀深度和量子阱周期对15μm中心距量子阱FPA的串音影响。

Abstract:

Quantum well FPA with grating coupling structure is hard to fabricate while the reflective structure is easier when the pixel is small. To confirm that whether the RC structure can take place the GC structure, we simulate the performance on anti-optical crosstalk of the Quantum Well FPA with GC structure or the RC structure by the FDTD software MEEP when pixel’s size is under the diffraction condition, and we prove that the RC structure shows better performance when the size of FPA’s cell is between 5-6.5μm and 8.5-10μm while the GC structure performs better when the cell size is between 6.5-8.5μm and 10-12μm, and these 2 kinds of structure show the close performance when the cell size is between 12-15μm And we have figured out that how the reflective angle, etch depth and the period of the quantum wellinfluence the the FPA’s ability of fight against the optical crosstalk with the RC structrue and a15μm cell size.