Source wavefront generation for a non-interferometric reconfigurable null test using a photonic lantern

A method is presented to use a fiber-optic device known as a photonic lantern to generate a reconfigurable custom wavefront for a null test of spherical, aspheric, and freeform optical surfaces. By modulating input intensity and phases at single-mode fiber ports, the output light field from the multimode end can be controlled to generate a custom nulling wavefront. Generation of a desired wavefront is demonstrated by simulating a nineteen-port, non-mode-selective photonic lantern. Using a response-matrix inversion approach, a wavefront with an RMS error of 71nm from its target was generated in simulation. A compact form-factor non-interferometric null test for freeform optical surfaces is then simulated to demonstrate utilizing the photonic lantern in a reconfigurable null test of a freeform optic.