Acousto-optically driven lensless single-shot ultrafast optical imaging

• Published in: Light, science & applications Vol. 11; no. 1; p. 66
• Main Authors: Touil, Mohamed, Idlahcen, Saïd, Becheker, Rezki, Lebrun, Denis, Rozé, Claude, Hideur, Ammar, Godin, Thomas
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 23.03.2022; Springer Nature B.V; Nature Publishing Group
• Subjects: 639/624/1107/510; 639/624/1111/1116; Applied and Technical Physics; Atomic; Classical and Continuum Physics; Engineering Sciences; Frequency; Lasers; Molecular; Optical and Plasma Physics; Optical Devices; Optics; Photography; Photonic; Photonics; Physics; Physics and Astronomy; Temporal variations
• ISSN: 2047-7538; 2095-5545; 2047-7538
• DOI: 10.1038/s41377-022-00759-y

Driven by many applications in a wide span of scientific fields, a myriad of advanced ultrafast imaging techniques have emerged in the last decade, featuring record-high imaging speeds above a trillion-frame-per-second with long sequence depths. Although bringing remarkable insights into various ultrafast phenomena, their application out of a laboratory environment is however limited in most cases, either by the cost, complexity of the operation or by heavy data processing. We then report a versatile single-shot imaging technique combining sequentially timed all-optical mapping photography (STAMP) with acousto-optics programmable dispersive filtering (AOPDF) and digital in-line holography (DIH). On the one hand, a high degree of simplicity is reached through the AOPDF, which enables full control over the acquisition parameters via an electrically driven phase and amplitude spectro-temporal tailoring of the imaging pulses. Here, contrary to most single-shot techniques, the frame rate, exposure time, and frame intensities can be independently adjusted in a wide range of pulse durations and chirp values without resorting to complex shaping stages, making the system remarkably agile and user-friendly. On the other hand, the use of DIH, which does not require any reference beam, allows to achieve an even higher technical simplicity by allowing its lensless operation but also for reconstructing the object on a wide depth of field, contrary to classical techniques that only provide images in a single plane. The imaging speed of the system as well as its flexibility are demonstrated by visualizing ultrashort events on both the picosecond and nanosecond timescales. The virtues and limitations as well as the potential improvements of this on-demand ultrafast imaging method are critically discussed. We demonstrate a versatile and user-friendly ultrafast single-shot imaging technique based on a simple and flexible acousto-optics spectro-temporal shaping stage combined with digital in-line holography.