title: Midfocus matching: a method for calculating lens positions for a Gaussian beam in a two-lens system.
abstract: For the situation in which a specific laser beam waist is required at a certain position, we develop a practical method of selecting focal lengths for a combination of two lenses and of calculating their positions. The method provides, in an easy graphical way, the solution of this two-lens focusing problem of Gaussian beams by finding the crossing point of two parametric curves.
authors.forename: F
authors.initials: F
authors.lastname: Keijzer
authors.forename: R J
authors.initials: RJ
authors.lastname: Lahaye
authors.forename: S
authors.initials: S
authors.lastname: Stolte