A new conception " optical ballast " is introduced for the first time as our knowledge . optical ballast can be used to decrease the variation of beam propagation characteristic due to the disturbance of refractive index of the medium . two types of optical ballast are described ( 7 )首次提出了“光学镇定器”的概念，并描述了两种类型的光学镇定器，它可用于减弱介质折射率的扰变对光束传播特性的影响。
