Photography optics in the time dimension

Heshmat, Barmak; Tancik, Matthew; Satat, Guy; Raskar, Ramesh

doi:10.1038/s41566-018-0234-0

“…In our application, the scene is static and repeated pulsed illumination with a scanning of the slit allows to reconstruct images with high spatial and temporal resolutions. In this frame, considerable breakthroughs in 3D scene reconstructions by ToF imaging were made by MIT [18][19][20][21][22][23] . Before reaching the streak tube, a pulsed laser beam travelling through a scene interacts with objects through a variety of processes: specular and diffuse reflection (sometimes multiple times), subsurface interactions, or diffraction.…”

mentioning

confidence: 99%

Stray light characterization with ultrafast time-of-flight imaging

Clermont

¹

,

Uhring

²

,

Georges

³

2021

Sci Rep

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Understanding stray light (SL) is a crucial aspect in the development of high-end optical instruments, for instance space telescopes. As it drives image quality, SL must be controlled by design and characterized experimentally. However, conventional SL characterization methods are limited as they do not provide information on its origins. The problem is complex due to the diversity of light interaction processes with surfaces, creating various SL contributors. Therefore, when SL level is higher than expected, it can be difficult to determine how to improve the system. We demonstrate a new approach, ultrafast time-of-flight SL characterization, where a pulsed laser source and a streak camera are used to record individually SL contributors which travel with a specific optical path length. Furthermore, the optical path length offers a means of identification to determine its origin. We demonstrate this method in an imaging system, measuring and identifying individual ghosts and scattering components. We then show how it can be used to reverse-engineer the instrument SL origins.

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“…In related work, cavities have been used for single-channel orbital angular momentum and wavelength to time conversion 28,29 . Aligned optical cavities have been used for time-folded optical imaging modalities like multi-pass microscopy 30,31 . Our implementation instead employs a re-imaging cavity as the means to obtain temporal resolution for wide-field imaging.…”

Section: Resultsmentioning

confidence: 99%

“…Periodic V ( t ) could also be used to implement wide-field lock-in detection. Traditional fast-imaging applications in plasma physics, laser-induced breakdown spectroscopy, combustion, time-of-flight techniques, and fluid dynamics could also benefit from sensitive single-shot imaging 6,31,50–52 . The n -frame tilted mirror re-imaging cavity is unique in its ability to perform single-shot ultrafast imaging of weak, non-repetitive events with zero deadtime between frames when using an internal PC gate (Supplementary Fig.…”

Section: Discussionmentioning

confidence: 99%

Electro-optic imaging enables efficient wide-field fluorescence lifetime microscopy

Bowman

¹

,

Klopfer

²

,

Juffmann

³

et al. 2019

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Nanosecond temporal resolution enables new methods for wide-field imaging like time-of-flight, gated detection, and fluorescence lifetime. The optical efficiency of existing approaches, however, presents challenges for low-light applications common to fluorescence microscopy and single-molecule imaging. We demonstrate the use of Pockels cells for wide-field image gating with nanosecond temporal resolution and high photon collection efficiency. Two temporal frames are obtained by combining a Pockels cell with a pair of polarizing beam-splitters. We show multi-label fluorescence lifetime imaging microscopy (FLIM), single-molecule lifetime spectroscopy, and fast single-frame FLIM at the camera frame rate with 103–105 times higher throughput than single photon counting. Finally, we demonstrate a space-to-time image multiplexer using a re-imaging optical cavity with a tilted mirror to extend the Pockels cell technique to multiple temporal frames. These methods enable nanosecond imaging with standard optical systems and sensors, opening a new temporal dimension for wide-field low-light microscopy.

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“…In our application, the scene is static and repeated pulsed illumination with a scanning of the slit allows 2 to reconstruct images with high spatial and temporal resolutions. In this frame, considerable breakthroughs in 3D scene reconstructions by ToF imaging were made by MIT [11][12][13][14][15][16] . Before reaching the streak tube, a pulsed laser beam travelling through a scene interacts with objects through a variety of processes: specular and diffuse reflection (sometimes multiple times), subsurface interactions, or diffraction.…”

Section: Introductionmentioning

confidence: 99%

“…Before reaching the streak tube, a pulsed laser beam travelling through a scene interacts with objects through a variety of processes: specular and diffuse reflection (sometimes multiple times), subsurface interactions, or diffraction. Suitable processing allows applications such as observing occluded objects 11,12 , observing light travelling through complex scenes 13,14 , retrieving three-dimensional reflectance function of surfaces on very-wide angles 15 , or more recently multi-zoom and multi-spectral imaging 16 .…”

Section: Introductionmentioning

confidence: 99%

Stray Light Characterization With Ultrafast Time-of-flight Imaging

Clermont

¹

,

Uhring

²

,

Georges

³

2021

Preprint

View full text Add to dashboard Cite

Understanding stray light (SL) is a crucial aspect in the development of high-end optical instruments, for instance space telescopes. As it drives image quality, SL must be controlled by design and characterized experimentally. However, conventional SL characterization methods are limited as they do not provide information on its origins. The problem is complex due to the diversity of light interaction processes with surfaces, creating various SL contributors. Therefore, when SL level is higher than expected, it can be difficult to determine how to improve the system. We demonstrate a new approach, ultrafast time-of-flight SL characterization, where a pulsed laser source and a streak camera are used to record individually SL contributors which travel with a specific optical path length. Furthermore, the optical path length offers a means of identification to determine its origin. We demonstrate this method in an imaging system, measuring and identifying individual ghosts and scattering components. We then show how it can be used to reverse-engineer the instrument SL origins.

show abstract

Photography optics in the time dimension

Cited by 11 publications

References 34 publications

Stray light characterization with ultrafast time-of-flight imaging

Stray light characterization with ultrafast time-of-flight imaging

Electro-optic imaging enables efficient wide-field fluorescence lifetime microscopy

Stray Light Characterization With Ultrafast Time-of-flight Imaging

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