论文标题
手性激发和有效的带宽增强倾斜的光波导晶格
Chiral excitation and effective bandwidth enhancement in tilted coupled optical waveguide lattices
论文作者
论文摘要
光逃离与波导晶格的光学波导侧耦合提供的光子类似物在一维空腔阵列中的激发两级原子的自发发射过程的光子类似物。根据费米的黄金规则，当原子共振频率落在晶格的停止频带中时，可以防止衰减过程，而时反转对称性可确保自发发射的光子在阵列的相对方向上具有同等的传播可能性。当量子发射极以恒定速度沿晶格漂移时，这种情况会大大修改。在波导光学类似物中，通过从晶格轴上引入波导轴的微小几何倾斜来模拟原子漂移。在这种设置中，阵列中的光激发是手性的，即，即使波导与紧密结合的晶格频段远远不相差，光线也沿晶格的首选方向传播。
Light escape from an optical waveguide side-coupled to a waveguide lattice provides a photonic analogue of the spontaneous emission process of an excited two-level atom in a one-dimensional array of cavities. According to the Fermi golden rule the decay process is prevented when the atomic resonance frequency falls in a stop band of the lattice, while time-reversal symmetry ensures that the spontaneously emitted photon has equal probability to propagate in opposite directions of the array. This scenario is drastically modified when the quantum emitter drifts along the lattice at a constant speed. In the waveguide optics analogue the atomic drift is emulated by the introduction of a slight geometric tilt of the waveguide axis from the lattice axis. In this setting light excitation in the array is chiral, i.e. light propagates in a preferred direction of the lattice, and coupling is allowed even though the waveguide is far detuned from the tight-binding lattice band.
