采用几何光学对三维发光体的透镜成像问题进行了研究。考虑到成像光锥的贡献,在近轴近似下,得到了用发光体的辐射强度表示像平面上照度分布的积分表达式,由此得到下列结果:1)沿光路上每一垂直于光路的平面上能量贡献是一样的。2)由于光路积分,探测器测到的光强涨落的幅度小于实际的涨落幅度,但在一定的条件下,发光体的涨落图像可重现。

The image formation of luminor body by lens is studied using geometrical optics. Considering the contributions due to viewed cone centred on the object point and extending through the luminnor body, the distribution of intensity in the image plane can be expressed by the integration of emitted powers of luminor body over the entire sightline under the paraxial approximation. Then following results obtained: 1) the contribution of emitted power in any plane perpendicular to the sightline is all the same. 2) the relative level of the intensity fluctuations measured by detector is smaller than the true value due to the integration, but the emission fluctuations of luminor body can be reconstructed under some conditions.