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

Alexandropoulos, Christos; Duocastella, Martí

doi:10.1016/j.optlaseng.2023.107692

Cited by 5 publications

(2 citation statements)

References 37 publications

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“…In these cases, the interaction between ultrasound waves and light enables unprecedented control of light at microsecond time-scales [46]. For instance, tunable acoustic gradient index of refraction lenses (or TAG lenses) are today employed as varifocal lenses in remote focussing systems [47][48][49][50][51], acousto-optic tunable filters are often implemented as electronically adjustable narrow-band-pass filters [52][53][54], and acousto-optic modulators (AOMs) are used for a fast modulation of the diffracted beam intensity [55]. Arguably, though, the acousto-optic method that holds the greatest potential in neuroscience involves acousto-optic deflectors (AODs).…”

Section: Introductionmentioning

confidence: 99%

Acousto-optic deflectors in experimental neuroscience: overview of theory and applications

Ricci,

Sancataldo,

Gavryusev

et al. 2024

J. Phys. Photonics

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Cutting-edge methodologies and techniques are required to understand complex neuronal dynamics and pathological mechanisms. Among them, optical tools stand out due to their combination of non-invasiveness, speed, and precision. Examples include optical microscopy, capable of characterizing extended neuronal populations in small vertebrates at high spatiotemporal resolution, or all-optical electrophysiology and optogenetics, suitable for direct control of neuronal activity. However, these approaches necessitate progressively higher levels of accuracy, efficiency, and flexibility of illumination for observing fast entangled neuronal events at a millisecond time-scale over large brain regions. A promising solution is the use of acousto-optic deflectors (AODs). Based on exploiting the acousto-optic effects, AODs are high-performance devices that enable rapid and precise light deflection, up to MHz rates. Such high-speed control of light enables unique features, including random-access scanning or parallelized multi-beam illumination. Here, we survey the main applications of AODs in neuroscience, from fluorescence imaging to optogenetics. We also review the theory and physical mechanisms of these devices and describe the main configurations developed to accomplish flexible illumination strategies for a better understanding of brain function.

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Section: Introductionmentioning

confidence: 99%

Acousto-optic deflectors in experimental neuroscience: overview of theory and applications

Ricci,

Sancataldo,

Gavryusev

et al. 2024

J. Phys. Photonics

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“…Optical microscopy has become the tool of choice in a myriad of relevant applications such as diagnostics [ 1 ], [ 2 ], neuroscience [ 3 ], fluid dynamics [ 4 ], and industrial inspection [ 5 ]. Compared to other characterization techniques, it offers key advantages including the possibility for non-invasive imaging of dynamic events, sub-micrometric spatial resolution, and direct access to the recorded information.…”

Section: Introductionmentioning

confidence: 99%

Scan-less microscopy based on acousto-optic encoded illumination

Marchese,

Ricci,

Saggau

et al. 2024

Nanophotonics

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Several optical microscopy methods are now available for characterizing scientific and industrial processes at sub-micron resolution. However, they are often ill-suited for imaging rapid events. Limited by the trade-off between camera frame-rate and sensitivity, or the need for mechanical scanning, current microscopes are optimized for imaging at hundreds of frames-per-second (fps), well-below what is needed in processes such as neuronal signaling or moving parts in manufacturing lines. Here, we present a scan-less technology that allows sub-micrometric imaging at thousands of fps. It is based on combining a single-pixel camera with parallelized encoded illumination. We use two acousto-optic deflectors (AODs) placed in a Mach–Zehnder interferometer and drive them simultaneously with multiple and unique acoustic frequencies. As a result, orthogonal light stripes are obtained that interfere with the sample plane, forming a two-dimensional array of flickering spots – each with its modulation frequency. The light from the sample is collected with a single photodiode that, after spectrum analysis, allows for image reconstruction at speeds only limited by the AOD’s bandwidth and laser power. We describe the working principle of our approach, characterize its imaging performance as a function of the number of pixels – up to 400 × 400 – and characterize dynamic events at 5000 fps.

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