Influence of Surface Tilt Angle on a Chromatic Confocal Probe with a Femtosecond Laser

Influence of Surface Tilt Angle on a Chromatic Confocal Probe with a Femtosecond Laser

This paper presents an intentional investigation of the effect of the object tilt angle on the tracking local minimum method (TL method), which is the one for detecting the measurement target position of the object optical axis, in a chromatic confocal probe employing a differential dual-fiber-detector optical system with a mode-locked femtosecond laser as the light source. The effect of the object tilt angle on dual-detector confocal probes, and even chromatic confocal probes, has not been investigated in detail so far, although the effect of object tilt angle on scanning confocal probes has been studied. At first, to examine the influence of the object tilt angle on the TL method, a theoretical model is established, and numerical simulations are performed based on the established theoretical equation. Then, the effect of aberrations in confocal optics on the confocal response curve is investigated in experiments. Finally, investigations on the effect of the object tilt angle on the TL method are demonstrated in experiments.

本文对物体倾斜角对跟踪局部最小值法（TL法）的影响进行了深入研究。在以锁模飞秒激光为光源的差分双光纤探测器光学系统的色共焦探头中，TL法用于检测物体光轴的测量目标位置。尽管已经研究了物体倾斜角对扫描共焦探头的影响，但到目前为止，物体倾斜角对双探测器共焦探头，甚至色共焦探头的影响尚未得到详细研究。首先，为了检验物体倾斜角对TL法的影响，建立了一个理论模型，并基于所建立的理论方程进行了数值模拟。然后，通过实验研究了共焦光学中的像差对共焦响应曲线的影响。最后，通过实验证明了物体倾斜角对TL法的影响。