论文标题
从有关光学活动的启发式角度看
On a heuristic point of view concerning the optical activity
论文作者
论文摘要
最近的发现是，菲涅耳对手性介质中光活性的现象学描述不是自谐的，我们对平面光波极化的性质进行了彻底的研究。我们证明光的极化是其量子力学特性之一的反射，称为准旋转。出乎意料的是，对于实验室坐标系，准旋转不是可观察到的。相反，它是关于动量依赖性局部坐标系的。准旋转的代表操作员是保利矩阵。波函数是琼斯向量。为了完全确定两极分化状态，需要两种不同种类的自由度。一个是表征准旋转状态的自由度。它们是stokes参数，是琼斯向量描述的状态下保利矩阵的期望值。另一个是指定局部坐标系的自由度，包括传播方向和周围的旋转角度。因此，有两种独立的机制来改变极化状态。一种是在固定的局部坐标系中更改准旋转状态。这是传统的机制，可以表示为琼斯向量的su（2）旋转。另一个是改变固定在其中的准旋转状态的局部坐标系。最后，我们证明是新识别的机制来解释光学活动。
Motivated by a recent finding that Fresnel's phenomenological description of the optical activity in the chiral medium is not self-consistent, we conduct a thorough investigation into the nature of the polarization of a plane light wave. We demonstrate that the polarization of light is the reflection of one of its quantum-mechanical properties, called the quasi-spin. Unexpectedly, the quasi-spin is not an observable with respect to the laboratory coordinate system. Instead, it is with respect to the momentum-dependent local coordinate system. The representative operators for the quasi-spin are the Pauli matrices. The wavefunction is the Jones vector. In order to completely determine a state of polarization, two different kinds of degrees of freedom are needed. One is the degrees of freedom to characterize the state of quasi-spin. They are the Stokes parameters, the expectation values of the Pauli matrices in the state described by the Jones vector. The other is the degrees of freedom to specify the local coordinate system, including the propagation direction and an angle of rotation about it. Accordingly, there are two independent mechanisms to change the state of polarization. One is to change the state of quasi-spin in a fixed local coordinate system. This is the traditional mechanism that can be expressed as an SU(2) rotation of the Jones vector. The other is to change the local coordinate system with the state of quasi-spin remaining fixed in it. At last, we show that it is the newly-identified mechanism that accounts for the optical activity.
