体全息在共焦显微镜中的应用

Application of Volume Hologram on Confocal Microscopy

采用体全息记录信息代替共焦显微镜中的反射镜,在物光的衍射光强最大的条件下,记录体全息信息.体全息共焦成像的动态范围取决于全息衍射效率和材料的限制,而深度分辨率则取决于物镜的数值孔径和记录介质的厚度大小.体全息共焦显微镜系统的观测结果对探测器前的光阑孔径大小没有明显的依赖关系,在探测器前加尺寸不必特别小的针孔或可以不加针孔,这样可减小由于衍射现象引起的像差.体全息成像本身具有滤波的作用.物镜的像差在体全息自成像过程中由于相位共轭而消除,从而使仪器的深度分辨率与测量的动态范围不再相互限制.

We use a 1-cm^3 LiNbO3 ： Fe as a holographic medium that is set in the experimental set up. When the maximum of the diffraction density of the object light is reached, the volume hologram information is t recorded in the medium. The dynamic range of volume hologram imaging depends on the hologram diffraction effidency and the material. The depth resolution depends on the numerical aperture of the objective lens and the thickness of the hologram. The result of observation musm＇ t dearly depend on the size of diaphragm. The pinhole before the detector musm＇ t be very small and may be removed, then we may decrease the shape distinction. The volume hologram possesses the function of filter. The shape distinction of object lens may be eliminated because of the phase conjugation during the volume hologram self-imaging. The dynamic range of measure and the depth resolution doesn＇t confine each other.