论文标题
波导微孔谐振器的纯圆极化光发射
Pure circularly polarized light emission from waveguide microring resonators
论文作者
论文摘要
循环极化光在许多应用中起着关键作用，包括光谱，显微镜和原子系统的控制。特别是在后者中，通常需要高极化纯度。原子控制的集成技术正在迅速发展，但是虽然积分光子学可以生成具有纯线性极化的场，但尚未解决高度纯圆极化状态的集成产生。在这里，我们表明，波导微孔谐振器，用方位角光栅扰动，从而发出带有光轨道角动量的光束，可以产生高圆形极化纯度的辐射场。我们通过利用结构和辐射模式的对称性，直接利用引导模式的横向和纵向场分量来实现这一目标。在排放轴和最大强度的轴上，我们在整个共振FWHM上的相对强度的平均极化杂质为$ 1.0 \ times 10^{ - 3} $，并在此范围内观察到低于$ 10^{ - 4} $的杂质。这构成了对$ {\ sim} 10^{ - 2} $杂质在集成设备上证明的杂质的显着改进。允许高圆极化纯度的光子结构可能有助于实现原子量子系统中的高保真控制和测量。
Circularly polarized light plays a key role in many applications including spectroscopy, microscopy, and control of atomic systems. Particularly in the latter, high polarization purity is often required. Integrated technologies for atomic control are progressing rapidly, but while integrated photonics can generate fields with pure linear polarization, integrated generation of highly pure circular polarization states has not been addressed. Here, we show that waveguide microring resonators, perturbed with azimuthal gratings and thereby emitting beams carrying optical orbital angular momentum, can generate radiated fields of high circular polarization purity. We achieve this in a passive device by taking advantage of symmetries of the structure and radiated modes, and directly utilizing both transverse and longitudinal field components of the guided modes. On the axis of emission and at maximum intensity, we measure an average polarization impurity of $1.0 \times 10^{-3}$ in relative intensity across the resonance FWHM, and observe impurities below $10^{-4}$ in this range. This constitutes a significant improvement over the ${\sim}10^{-2}$ impurity demonstrated in previous work on integrated devices. Photonic structures allowing high circular polarization purity may assist in realizing high-fidelity control and measurement in atomic quantum systems.
