Figure 3.

Drawing of the scanning process. Each orange square represents a residence time of the laser. During this dwell time, the photomultiplier counts the number of incoming photons, thus determining the pixel value of the final image. The laser beam follows the black arrows over the area to create an image. The red arrows show the path back to the starting position for a controlled dead time. In this simplistic example of a 4 × 4 pixel image, the return to the starting position requires 4 additional dwell times.