偏振光的真实逻辑

胡良

深圳市宏源清实业有限公司

摘要：光（电磁波）是横波，振动方向与光波前进方向构成的平面称为振动面；振动方向相对于传播方向的不对称性就称为偏振，具有偏振属性的光就称为偏振光。

关键词：光子，偏振光，信号速度

分类号：O412,O413

作者：总工，高工，硕士，副董事长

1偏振光的内涵

光（电磁波）是横波，振动方向与光波前进方向构成的平面称为振动面；振动方向相对于传播方向的不对称性就称为偏振，具有偏振属性的光就称为偏振光。

如果，光的振动面只限于某一固定方向的，就称为平面偏振光（线性偏振光）。偏振是横波与纵波区别的标志（横波才具有偏振现象）；可借助于偏振片检测光的偏振属性。

光波中的电振动矢量及磁振动矢量都与传播速度垂直，可见，光波具有偏振性，因此光波是横波。

Light (electromagnetic wave) is a transverse wave, and the plane formed by the direction of vibration and the direction of light wave is called the vibration plane; the asymmetry of the vibration direction relative to the propagation direction is called polarization, and light with polarization properties is called polarized light.

If the vibration plane of light is limited to a certain fixed direction, it is called plane polarized light (linearly polarized light). Polarization is the sign of the difference between transverse wave and longitudinal wave (transverse wave has polarization phenomenon); the polarization properties of light can be detected by means of polarizer.

Both the electric vibration vector and the magnetic vibration vector in the light wave are perpendicular to the propagation speed. It can be seen that the light wave is polarized, so the light wave is a transverse wave.

偏振光是指光矢量振动方向保持不变（或依据某种规则变化）的光波。根据其属性,偏振光可分为平面偏振光（线偏振光），圆偏振光（或椭圆偏振光）及部分偏振光。

从另一个角度来看，横波具有一个特性，其振动是具有极性。在与传播方向垂直的平面上，其可向任一方向振动（通常将光波电场振动方向视为光振动方向）。如果，光波都在同一方向上振动，就称为偏振光（完全偏振光）。自然光在各个方向振动是均匀分布的，属于非偏振光。

Polarized light refers to a light wave whose vibration direction of the light vector remains unchanged (or changes according to a certain rule). According to its properties, polarized light can be divided into plane polarized light (linearly polarized light), circularly polarized light (or elliptically polarized light) and partially polarized light.

From another point of view, the transverse wave has a characteristic, its vibration is polar. On a plane perpendicular to the propagation direction, it can vibrate in any direction (usually the direction of the light wave electric field vibration is regarded as the direction of light vibration). If the light waves vibrate in the same direction, it is called polarized light (fully polarized light). Natural light vibrates evenly in all directions and belongs to unpolarized light.

具体来说，

第一类，平面偏振光

平面偏振光（或线偏振光）是指，光波电矢量振动方向只局限在一个确定的平面内；由于振动方向在传播过程中持一条直线，因此，可称为线偏振光。

换句话说，光矢量端点的轨迹是直线；而光矢量只沿着一个确定方向振动，其大小随相位变化，方向保持不变。

Specifically,

The first type, plane polarized light

Plane polarized light (or linearly polarized light) means that the direction of the electric vector of light waves is limited to a certain plane; because the direction of vibration is a straight line during the propagation process, it can be called linearly polarized light.

In other words, the trajectory of the end point of the light vector is a straight line; while the light vector only vibrates in a certain direction, its magnitude changes with the phase, and the direction remains unchanged.

第二类，椭圆偏振光

椭圆偏振光（或圆偏振光）是指，光波电矢量随时间作有规则地改变；电矢量末端轨迹在垂直于传播方向的平面上呈椭圆形（或圆形）。

换句话说，光矢量端点的轨迹是一个椭圆（或圆）；而光矢量不断旋转，其大小及方向随时间有规律的变化。

The second type, elliptically polarized light

Elliptical polarized light (or circularly polarized light) means that the electric vector of light waves changes regularly over time; the end track of the electric vector is elliptical (or circular) on a plane perpendicular to the direction of propagation.

In other words, the trajectory of the end point of the light vector is an ellipse (or circle); while the light vector continuously rotates, its size and direction change regularly with time.

第三类，部分偏振光

部分偏振光是指，光波电矢量振动在传播过程中，在某一确定方向上具有相对优势偏振光。

换句话说，在垂直于光传播方向的平面上，含有各种振动方向的光矢量，而光振动在某一方向更显著，这意味着，部分偏振光就是自然光及完全偏振光的叠加。

The third category, partially polarized light

Partially polarized light refers to the relatively dominant polarized light in a certain direction during the propagation of the electric vector vibration of light waves.

In other words, on a plane perpendicular to the light propagation direction, there are light vectors in various vibration directions, and light vibration is more pronounced in a certain direction, which means that partially polarized light is the superposition of natural light and fully polarized light.

此外，

可使平面偏振光振动面发生旋转的物质，就称为旋光性物质；而不能使平面偏振光振动面发生旋转的物质，就称为非旋光性物质。旋光物质使偏振光旋转的角度就称为旋光度。

当光线照射在物体上被偏向某个方向折射的现象就是偏振光现象。宇宙具有核式结构，因此，宇宙微波背景具有偏振光效应。

In addition,

A substance that can rotate the plane of plane-polarized light is called an optically active substance; while a substance that cannot rotate the plane of plane-polarized light is called a non-optically active substance. The angle at which an optically active substance rotates polarized light is called the optical rotation.

The phenomenon that light shining on an object is deflected and refracted in a certain direction is the phenomenon of polarized light. The universe has a nuclear structure, so the cosmic microwave background has a polarization effect.

2宏观的偏振状态

类比于偏振光，可解析宏观的偏振态。

从宏观的角度来看，飞行器（内禀纵波属性）围绕地球（内禀纵波）进行椭圆（或圆周）运动；则飞行器与地球相互之间体现为相对横波属性。

Analogous to polarized light, it can analyze the macroscopic polarization state.

From a macro point of view, the aircraft (intrinsic longitudinal wave property) moves around the earth (intrinsic longitudinal wave) in an elliptical (or circular) motion; then the aircraft and the earth reflect relative transverse wave properties.

第一种情况

如果飞行器的运动轨迹只局限在一个确定的圆周；由于运动轨迹在运动过程中，沿着一条固定的轨道；因此，飞行器具有线偏振状态。

First case

If the trajectory of the aircraft is only limited to a certain circle; because the trajectory of the motion is along a fixed trajectory during the movement, the aircraft has a linear polarization state.

第二种情况，

如果飞行器的运动方向随时间作有规则地改变；飞行器的运动轨迹在垂直于运动方向的平面上，同时保持自旋；则飞行器具有椭圆偏振（或圆偏振）状态。

In the second case,

If the moving direction of the aircraft changes regularly over time; the moving track of the aircraft is on a plane perpendicular to the direction of movement while maintaining spin; the aircraft has an elliptical polarization (or circular polarization) state.