Cophasing multiple aperture telescopes with Linearized Analytic Phase Diversity (LAPD)

Focal plane wavefront sensing is an appealing technique to cophase multiple aperture telescopes. Phase diversity, operable with any aperture configuration or source extension, generally suffers from high computing load. In this Letter, we introduce, characterize and experimentally validate the LAPD algorithm, based on a fast linearized phase diversity algorithm rev{with a capture range comparable to classic phase diversity.} We demonstrate that a typical performance of lambda/75 RMS wavefront error can be reached.