摘要 |
A system includes an objective lens, an imaging module, and a measurement module. The objective lens is configured to receive light emitted by a light source, focus the emitted light onto a target object, and receive light reflected by the target object. The imaging module is configured to receive a first portion of the reflected light. The measurement module is configured to receive a second portion of the reflected light and includes a photo detector and an astigmatic lens configured to direct the second beam onto the photo detector. |