Reliable profile reconstruction of GRIN lenses produced by ion-exchange processes

We propose a method that allows for a fast and accurate reconstruction of the refractive index profile of radially symmetric gradient index lenses fabricated by ion-exchange processes. The presented method enables the reconstruction of the profile up to the 10th polynomial order without direct spatially resolved refractive index measurements. It requires as input a working distance measurement at the paraxial limit and an accurate wavefront aberration measurement at full aperture. In addition, the approach combines the information about the optical behavior with the knowledge about the overall mass density changes of the glass rods during the ion exchange production processes to refine the reconstruction. Finally, the reconstruction of multiple profiles produced with different boundary conditions is demonstrated and confirms the functionality of the method.