定义：
将两个偏振激光光束合在一起的技术。

偏振合束（或者偏振耦合）是将两线偏振激光光束合在一起的技术。 

非相干偏振合束 
非相干合束是较简单的情形。例如，两个大面积的激光二极管的出射光束中，一个是垂直偏振，另一个为水平偏振，将光束射向薄膜偏振片后，一束光被反射，而另一束光透射，并且两束光的传播方向是相同的。
因此，可以得到非偏振光束，功率是两入射光束的和（忽略寄生损耗），光束质量与入射光束相同。因此，光束的亮度加倍。 
这一技术通常用于端泵浦固态激光器中。只有当激光晶体可以同时吸收两个方向的泵浦光时才能实现。Nd:YAG就是此种情况，而[[Nd:YVO4]]则不是。 
非相干偏振合束不能认为是功率缩放的方法，因为它不可重复：它需要入射光束是偏振的，但是得到的出射光束是非偏振的。 

相干偏振合束 
如果将两个相干的光束进行偏振合束，可以得到线偏振的输出光。假设两入射光功率是相等的，得到的输出光的偏振态与任一入射光束偏振方向之间的夹角都是 45°。这一方法是相干光束合成的一种。、 
由于出射光是线偏振的，相干偏振合束可以重复多次。因此该技术适宜于功率缩放。 

Definition: a technique for combining two polarized laser beams

More general term: beam combining

Polarization beam combining (or polarization coupling) is a technique for combining (superimposing) two linearly polarized laser beams.

Incoherent Polarization Combining

The simpler variant is incoherent combining. For example, the output beams of two broad area laser diodes, one being vertically polarized and the other one horizontally polarized, can be sent onto a thin-film polarizer such that one of the beams is reflected, the other one transmitted, and both beams then propagate in the same direction. As a result, one obtains an unpolarized beam having the combined optical power of the input beams (neglecting some parasitic losses) and the same beam quality. Accordingly, the brightness is nearly doubled.

This technique is often used e.g. for end pumping of a solid-state laser with an increased power. It works only if the laser crystal can similarly well absorb pump radiation with both polarization directions. This is the case e.g. for Nd:YAG, but not for Nd:YVO₄.

Incoherent polarization beam combining can not be considered as a method for power scaling, as it is not repeatable: it requires polarized input beams and leads to an unpolarized output beam.

Coherent Polarization Combining

If two mutually coherent beams are polarization combined, it is possible to obtain a linear polarization state for the output. Assuming equal input powers for the two ports, the output polarization will be rotated by 45° with respect to the polarization direction of any of the input beams. The method is one variant of coherent beam combining.

Due to the linear output polarization, coherent polarization combining can be repeated many times. It is thus a technique suitable for power scaling.