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Transmission mode synthetic aperture interferometry using a compact coherent imager and switched fiber-optic illumination
journal contribution
posted on 2024-03-22, 11:17 authored by J Garcia-Armenta, Pablo RuizPablo Ruiz, Russ CoggraveRuss Coggrave, Jeremy CouplandJeremy CouplandThis paper discusses a modular implementation of synthetic aperture interferometry (SAI) using inexpensive telecommunications technologies that can be expanded for use in optical instruments with arbitrarily large fields of view. Exploiting multiple image sensors and multiple illumination sources, transmission and reflection SAI geometries, capable of emulating the phase contrast and interference modes of conventional interference microscopes, are considered. The point-spread and transfer characteristics of these geometries are illustrated for the case of a transmission mode instrument. It is shown that although imaging is strictly field dependent (i.e. shift-variant), the response of modular instruments is periodic and with careful choice of illumination and sensor positioning can be made quasi shift-invariant. We demonstrate SAI in a transmission configuration comprising of a single coherent imager that holographically records the field scattered from a test target sequentially illuminated by 16 different plane waves. This set-up is equivalent to a single module of a larger SAI system and since brightfield regions in the individual reconstructed images overlap, provides an ideal platform to examine the effect of tilt and phase offset errors in the illumination. By applying a first order correction and assuming phase continuity over the overlapping regions, we demonstrate a significant improvement in the SAI reconstruction.
Funding
Synthetic aperture interferometry: High-resolution optical measurement over an exceptionally large field of view
Engineering and Physical Sciences Research Council
Find out more...EPSRC Centre for Doctoral Training in Embedded Intelligence
Engineering and Physical Sciences Research Council
Find out more...Epigem Ltd
UK Government's Department for Business, Energy and Industrial Strategy (BEIS) through the UK's National Measurement System Programmes at NPL
History
School
- Mechanical, Electrical and Manufacturing Engineering
Published in
Optics and Lasers in EngineeringVolume
172Publisher
ElsevierVersion
- VoR (Version of Record)
Rights holder
© Crown CopyrightPublisher statement
This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Acceptance date
2023-09-15Publication date
2023-09-29Copyright date
2023ISSN
0143-8166eISSN
1873-0302Publisher version
Language
- en