Spacing ratio of two Fabry-Perot etalon in interference spectroscopy

Abstract

The free spectral range of two Fabry-Perot etalons in series as a function of their spacing ratio is systematically investigated by a new method, called method of « forbidden zones ». Its properties and directions for use are discussed. It gives the best ratios and surely. The important simplification of calculations and the reliability of results become primordial advantages in the case of more complicated chains. Other applications may be hoped.