Optimum principles of laser beam projection

The usual problem of laser beam projection ist the following: There are given e.g. the object side position and size of laser waist and the object and image-side focal lengths. This allows to calculate the image side position and size of laser waist (waist projection). A special problem of laser beam projection can be formulated as follows: A laser spot should be minimal in a given image side position relative to the object side position of laser waist and the focal length, respectively. That is, the optimal geometry of the laser beam projection (optimal focussing) is looked for as a function of the given parameters. All typical geometrical problems of this special case are treated on the basis of the ideal laser beam projection. The relevant formulas are deriven and the results discussed.