Video-rate quantitative phase imaging with dynamic acousto-optic defocusing

Various quantitative phase imaging techniques exist capable of characterizing transparent and low-contrast samples without the addition of dyes or fluorescent probes. Among them, the transport of intensity equation (TIE) allows phase retrieval by capturing information from different focal planes wit...

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Bibliographic Details
Authors: Alexandropoulos, Christos, Duocastella, Martí
Format: article
Status:Published version
Publication Date:2023
Country:España
Institution:Universidad de Barcelona
Repository:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/201839
Online Access:https://hdl.handle.net/2445/201839
Access Level:Open access
Keyword:Làsers
Òptica
Holografia acústica
Lasers
Optics
Acoustic holography
Description
Summary:Various quantitative phase imaging techniques exist capable of characterizing transparent and low-contrast samples without the addition of dyes or fluorescent probes. Among them, the transport of intensity equation (TIE) allows phase retrieval by capturing information from different focal planes without complex inteferometric setups. However, current implementations can be limited in speed or accuracy by the lack of optical systems suitable for fast, reliable, and customizable focal plane selection. Here, we report how combining acousto-optics with pulsed illumination enables accurate and on-demand electronic defocus control suitable for TIE phase imaging at speeds only limited by the camera frame rate. The system exhibits diffraction-limited spatial resolution and high reconstruction fidelity, undistinguishable from traditional mechanical defocusing. We demonstrate its feasibility by measuring different dynamic events at rates as high as 100 phase maps per second. The tunability and ease of implementation of our system can pave the way to democratizing quantitative phase imaging in histopathology, fluid dynamics, and other fields involving thin transparent samples.