Joint estimation of object and probes in vectorial ptychography

Arthur Baroni,Virginie Chamard,Peng Li,Patrick Ferrand,Marc Allain

doi:10.1364/oe.27.008143

Abstract

Vectorial ptychography has been recently introduced to reconstruct the Jones matrix of an anisotropic object by means of series of ptychographic measurements performed using a set of polarized illumination probes in conjugation with various analyzers. So far, the probes were assumed to be completely known (amplitude, wavefront, state of polarization), which is rarely the case in practice. Here we address the issue of the joint estimating of the set of polarized illumination probes together with the Jones matrix of an anisotropic object in vectorial ptychography. We propose an algorithm based on a conjugate gradient strategy. Experimental results are reported, showing an improvement on the object estimate, in addition to a precise reconstruction of the probes.

Highlights

Ptychography is an imaging technique aiming at reconstructing the transmission properties of an object, namely its transmittance and induced phase shift, by means of an iterative algorithm
We address the issue of the joint estimation of the probes together with the object in the context of vectorial ptychography
We have proposed an improvement of vectorial ptychography by implementing the joint estimation of the object’s Jones matrix together with the vectorial probes, based on the conjugate gradient strategy

Summary

Introduction

Ptychography is an imaging technique aiming at reconstructing the transmission properties of an object, namely its transmittance and induced phase shift, by means of an iterative algorithm. It exploits series of intensity diffraction patterns acquired by scanning the specimen with a finite-size coherent probe at controlled locations, and preserving a sufficient overlap between successive illuminated areas [1]. Uncertainties on the probe produce reconstruction artefacts [2], so that methods have been developed, based on a joint reconstruction of the probe together with the object This allowed a dramatic improvement of the obtained reconstructions [3, 4]. Ptychography opened new perspectives in optical microscopy for quantitative phase imaging [5,6,7]

Methods

Findings

Discussion

Conclusion