定义：可以滤除光学包层中的光的装置。

有些情况下，需要消除光纤包层中的光。例如： 

• 单模光纤有时被用作模清洁器。需要的光在光纤纤芯中传播，而其它的光由于会降低光束质量，因此需要消除。很多情况下，可以在光纤包层周围涂覆聚合物包层用做包层模式滤除器。这时，聚合物包层的折射率需要比光纤包层的稍大，这样光可以从光纤包层进入聚合物包层中，最后由不规则处的散射而辐射到周围的空气中。（或者包层可以吸收光。） 
• 由双包层光纤制作的高功率光纤放大器中，剩余（未被吸收的）泵浦光（在泵浦端相反的光纤端口处）需要从泵浦包层（内包层）中消除，防止其进入放大信号中或者进入信号光源中。这时需要采用一种特殊的包层模式滤除器。 
• 当将泵浦光注入到双包层光纤（例如，从自由空间中）中时，一部分光功率会进入泵浦包层周围的外包层中。它可以在外包层中传播到光纤的聚合物包层中，然后由于热效应损坏该包层。这一问题可以通过采用包层滤除器使外包层中的光衰减来解决。 

用在高功率光纤激光器和放大器中的包层模式滤除器需要承受很高的光学功率。需要保证这些功率在很宽的区域内被吸收，产生的热被安全移除，而不会损坏模式滤除器或周围的器件。 

Definition: devices which can remove light from a fiber cladding

In some situations, it is necessary to remove light from the cladding of an optical fiber. Some examples:

• Sometimes, a single-mode fiber is used as a kind of mode cleaner. The wanted light is transmitted through the fiber core, and any other light, spoiling the beam quality, should be removed. In many cases, a polymer coating around the fiber cladding can serve as a cladding mode stripper. For that purpose, the refractive index of the coating should be slightly above that of the cladding, so that light can easily be transmitted from the cladding into the coating and then radiated into the ambient air by scattering at irregularities. (Alternatively, the coating may absorb the light.)
• In a high-power fiber amplifier made from a double-clad fiber, residual (unabsorbed) pump light (at the fiber end opposite to the pump end) may have to be removed from the pump cladding (inner cladding) in order to prevent it either from accompanying the amplified signal or from getting to the signal source. A special cladding mode stripper may be used for that purpose.
• When pump light is launched into a double-clad fiber (for example, from free space), some of the optical power may get into the outer cladding around the pump cladding. It may propagate in that outer cladding up to a location where the fiber has a polymer coating, and then destroy that coating via excessive heating. That problem may be avoided with a cladding stripper which attenuates light in the outer cladding, but not in the pump cladding.

Cladding mode strippers for use in high-power fiber lasers and amplifiers need to be able to handle substantial optical powers. It needs to be ensured that these powers are absorbed in a sufficiently widespread region, and that the generated heat can be removed safely, without damaging the mode stripper or any surrounding parts.