Logo PTB

Focused Laser beam

The wave fronts of the focused laser beam shown are moving with the speed of light. In the focus the wave fronts get plane. This location is a preferred part of the beam for interferometrical applications.

All previous illustrations shown have been calculated using the assumptions of

H. Kogelnik, T. Li: ‘Laser Beams and Resonators’, IEEE vol. 54 1312-1329, 1966. 5, 26