球差对物距像距法测薄凸透镜焦距的影响

THE EFFECTS OF SPHERICAL ABERRATION ON MEASURING FOCUS OF THIN CONVEX LENS WITH OBJECT DISTANCE IMAGE DISTANCE METHOD

对轴上点球差给出了一种物理图像较为清楚的计算方法,得到了透镜的几何尺寸、位置及其介质与轴上点球差的关系式。在单色光、小物条件下,球差是引起薄凸透镜焦距的测量误差的主要因素。本文详尽地讨论了透镜的孔径、折射率、曲率半径对焦距的测量误差的影响,提出减小在物距像距法测薄凸透镜焦距时由球差引起的误差的方法。

The calculating method of the clear physical image was given for the spot spherical aberration on axis, the relational expressions of geometrical size, place and medium of lens and the spot spherical aberration on axis were deduced. Under conditions of monochromatic light and a small object, the spherical aberration was the main factor which led to measuring error of focus of thin convex lens. This paper minutely discussed the effects of aperture, refractive index and curvature radius of lens on measuring error of focus, suggested the method of decreasing the error which was caused by spherical aberration when the focus of thin convex lens was measured with object distance—image distance metho d.