Enhancement of magneto-optical effects in hybrid magneto-plasmonic systems has attracted considerable recent attention because of their potential for building non-reciprocal nanophotonic devices. Quantitative understanding of the fundamental origin and contributing mechanisms for the enhancement is crucial for optimizing applications. Here, we unravel different physical origins of the giant enhancement of Faraday rotation and ellipticity in a hybrid magneto-plasmonic system, namely, waveguided magneto-plasmonic crystal for excitation with transverse electric (TE) and transverse magnetic (TM) polarized light. With TE polarization excitation, where the surface plasmons are not directly excited, the natural weak value amplification of Faraday effects appearing due to the spectral domain interference of Fano resonance is the dominant cause of the enhancement. For TM polarization excitation, on the other hand, waveguide-plasmon strong coupling and its universal manifestation of avoided crossing plays an important role, leading to maximum enhancement of the magneto-optical effects in the avoided crossing regime.

混合磁等离子体系统中磁光效应的增强已经吸引了相当大的关注，因为它们具有构建不可逆的纳米光子器件的潜力。定量了解增强的基本来源和作用机制对于优化应用程序至关重要。在这里，我们揭示了混合磁等离子体系统中法拉第旋转和椭圆度的巨大增强的不同物理起源，即用于横向电（TE）和横向磁（TM）偏振光激发的波导磁等离子体晶体。在TE极化激发下，表面等离激元不被直接激发，由于法诺共振的频谱域干扰而出现的法拉第效应的自然弱值放大是增强的主要原因。另一方面，对于TM极化激励，波导-等离子体激元的强耦合及其避免交叉的普遍表现起着重要作用，从而导致在避免交叉状态下磁光效应的最大增强。