A new tool for the characterization of self-doubling crystals

The sphere method is a unique tool for a complete characterization of the parametric non linear optical properties of crystals, including phase-matching directions and effective coefficients. It uses a sample cut as a sphere with millimetric dimensions and mounted on an Euler circle after X-rays orientation. We report a theoretical investigation of the ability of an extension of the sphere method to study directly self-doubling crystals, based on the insertion of the sphere inside a laser cavity.