Detection of laser spot drift

A system for measuring the drift of laser spot is designed and the drift of a He-Ne laser beam is measured. With a CCD camera and a frame grabber to capture the laser spot, the digital image is transferred to special software for further processing, the amount of the laser spot drift can be achieved. The amount of the drift in X direction, Y direction and in spatial angle can be obtained through geometrical optics. The reason that causes the beam drift is analyzed. The result shows that the direction of the emergent beam from He-Ne laser is influenced mainly by temperature, vibration, air disturbance and laser structure. The system can accurately measure the laser beam drift and the control of the beam drift is implemented.