The manipulation of the polarization properties of light in guided media is crucial in many classical and quantum optical systems. However, the capability of current technology to finely define the state of polarization of particular wavelengths is far from the level of maturity in amplitude control. Here, we introduce a light-by-light polarization control mechanism with wavelength selectivity based on the change of the phase retardance by means of stimulated Brillouin scattering. Experiments show that any point on the Poincare sphere can be reached from an arbitrary input state of polarization with little variation of the signal amplitude (<2.5 dB). Unlike other Brillouin processing schemes, the degradation of the noise figure is small (1.5 dB for a full 2π rotation). This all-optical polarization controller can forge the development of new polarization-based techniques in optical communication, laser engineering, sensing, quantum systems, and light-based probing of chemical and biological systems.

中文翻译：

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布里渊波长选择性全光偏振转换

在许多经典和量子光学系统中，对导介质中光偏振特性的操纵是至关重要的。然而，当前技术精细定义特定波长偏振状态的能力远未达到幅度控制的成熟水平。在这里，我们通过受激布里渊散射引入了一种基于相位延迟变化的具有波长选择性的逐光偏振控制机制。实验表明，可以从任意输入极化状态到达庞加莱球上的任何点，信号幅度几乎没有变化 (<2.5 dB)。与其他布里渊处理方案不同，噪声系数的下降很小（完整 2π 旋转为 1.5 dB）。