Jakobsen Michael Linde, Hanson Steen Grüner
DTU Fotonik, Department of Photonics Engineering, Technical University of Denmark, P.O. Box 49, DK-4000, Roskilde, Denmark.
Appl Opt. 2012 Jul 1;51(19):4316-24. doi: 10.1364/AO.51.004316.
Objective speckles produced by two beams overlapping and interfering on a rough object surface contain information about the angle of incidence of the two beams, and how well they overlap. We obtain the autocovariance function for such a speckle pattern, and demonstrate how the information carried by the objective speckles can be used to probe the distance between the object and the observation plane. From a distance of 75 mm to a distance of 150 mm, and using an angle of 0.3 deg between the two incident beams, we can measure the actual distance with an uncertainty of better than ±0.1% of the full range. As long as the beams overlap at the object surface, the proposed method can measure distance with an uncertainty inversely proportional to the spot size at the object.
由两束光在粗糙物体表面重叠并干涉产生的目标散斑包含了两束光的入射角以及它们重叠程度的信息。我们获得了这种散斑图案的自协方差函数，并展示了目标散斑所携带的信息如何用于探测物体与观察平面之间的距离。在75毫米到150毫米的距离范围内，两束入射光之间的夹角为0.3度时，我们能够测量实际距离，其不确定度优于全量程的±0.1%。只要光束在物体表面重叠，所提出的方法就能以与物体处光斑尺寸成反比的不确定度来测量距离。
