Recorded 14 October 2022. Anne Sentenac of the Fresnel Institute presents "A unified description of 3D diffraction microscopy" at IPAM's Diffractive Imaging with Phase Retrieval Workshop. Abstract: The purpose of this talk is to present a general, unified description of optical diffraction microscopy using a common theoretical framework. The goal is not to delve into the details of the many different microscopy variations, nor to discuss how they can be implemented in practice, but rather to show how seemingly disparate variations can be summarized and categorized using two very basic concepts: the Helmholtz principle of reciprocity and the Green time-reversal identity. The formalism applies to essentially all diffraction microscopes, whether they be transmitting or reflecting, scanning or full-field, coherent or partially coherent. Learn more online at: http://www.ipam.ucla.edu/programs/workshops/workshop-i-diffractive-imaging-with-phase-retrieval/?tab=schedule