Micrometer accuracy method for small-scale laser focal spot centroid measurement

• The smaller the focal spot, the higher the required precision targeting.
• We present a brief description of a method of measuring the position of small-scale laser focal spots.
• We calculated the centroid position of the small-scale laser focal spot.
• This method could be useful in conjunction with high-repetition or cw alignment beams.

The measurement of the centroid of small-scale laser focal spot is one of the most promising technologies for small-scale laser focal spot precise positioning. A method of two-dimensional scanning with CCD has been conducted to precisely measure the centroid of the small-scale laser focal spot (diameter in microns) by obtaining the change curve for gray value. The theoretical analysis is consistent with the experimental results.