INSTITUT NATIONAL DE LA RECHERCHE SCIENTIFIQUE

A diffraction-gated real-time ultrahigh-speed mapping photography method and system, by probing a transient scene with a single-wavelength continuous-wave beam, imaging the probed transient scene, generating different replicated images of the transient scene at spatially separated positions by using a 4f imaging system and a spatial light modulator, and rescaling the images size onto a low-speed CMOS or CCD camera for example, synchronizing with the flipping of the spatial light modulator for recording images of the transient scene.

A method and a system for single-shot multi-frame ultrafast terahertz imaging of a scene, the method comprising generating a pump beam and a probe beam: generating a THz beam from the pump beam and passing the THz beam through the scene: multiplexing the probe beam in the time domain and in the spatial-frequency domain, yielding a multiplexed probe beam; detecting a THz beam passing through the scene; guiding the multiplexed probe beam to a THz detection crystal and converting the multiplexed probe beam into mutually orthogonal linear polarized beams; guiding the mutually orthogonal linear polarized beams to a camera; and recovering frames of the scene from multiplexed images acquired by the camera.

A method and a system for imaging a transient event, the method comprising passively recording spatiotemporal projections of the transient event in an angular range from −45° to +45°; and processing the recorded spatiotemporal projections by compressed sensing tomographic image reconstruction to recover the transient event. The system comprises an imaging unit and a shearing unit for imaging a dynamic event to different positions, a detector that records data by spatially integrating over each pixel and temporally integrating; and a processing unit that reconstructs the dynamic event from said data by compressed sensing tomographic image reconstruction.

A method and a system for imaging a dynamic scene, by time-spectrum mapping when a single chirped pulse probes the dynamic scene, storing temporal information at different wavelengths, spectral shearing, spatial encoding and reverse spectral shearing; spatiotemporal integration; and image reconstruction from a resulting captured snapshot, using a laser source configured to emit a linearly chirped laser probe pulse; an imaging unit; a shearing and reversing shearing unit; an encoder; a detector; and a computer; wherein the imaging unit is configured to record the linearly chirped laser probe pulse transmitted by the dynamic scene in a snapshot; the shearing and reversing shearing unit is configured to spectrally shears the linearly chirped laser pulses received from the imaging unit to the encoder, the detector records a compressed snapshot of a temporal information of the dynamic scene read out by the probe pulse; and the computer processes the snapshot and yields a(x,y,t) datacube of the dynamic scene.

A system and a method for single-shot compressed optical-streaking ultra-high-speed imaging, the system comprising a spatial encoding module spatially encoding the transient event with a binary pseudo-random pattern into spatially encoded frames; a galvanometer scanner temporally shearing the spatially encoded frames; and a CMOS camera receiving the temporally sheared spatially encoded frames, during one exposure time of the camera, for reconstructing the transient event. The method comprises spatial encoding a transient event; temporal shearing resulting spatially encoded frames of the event, spatio-temporal integration, and reconstruction.

A diffraction-gated real-time ultrahigh-speed mapping photography method and system, by probing a transient scene with a single-wavelength continuous-wave beam, imaging the probed transient scene, generating different replicated images of the transient scene at spatially separated positions by using a 4f imaging system and a spatial light modulator, and rescaling the images size onto a low-speed CMOS or CCD camera for example, synchronizing with the flipping of the spatial light modulator for recording images of the transient scene.

A method and a system for single-pixel of an object is provided for deterministic two-dimensional (2D) spatial patterns onto the imaging beam, followed by data acquisition using a single-pixel detector. In the ensuing image reconstruction, these spatial patterns are used as prior knowledge to facilitate the accurate recovery of spatial information. By eliminating the need for a 2D sensor such as CCD or CMOS, the method and system allow using detectors whose cutting-edge performance or high specialization are impractical to manufacture in an array format. laser scanning rapidly deploys individual encoding masks as optically selected sub-regions larger aggregate patterns that are displayed via DMD. Pattern aggregation enhances SPI data acquisition rates to more than two orders of magnitude above the limitations of DMD-only modulation, while still retaining the frame size and flexibility of pattern display with DMDs. Meanwhile, a fast CS reconstruction algorithm, which is tightly coupled with the architecture of pattern deployment, is developed with full compatibility with parallel computing for real-time visualization.

A method and a system for single-pixel of an object is provided for deterministic two-dimensional (2D) spatial patterns onto the imaging beam, followed by data acquisition using a single-pixel detector. In the ensuing image reconstruction, these spatial patterns are used as prior knowledge to facilitate the accurate recovery of spatial information. By eliminating the need for a 2D sensor such as CCD or CMOS, the method and system allow using detectors whose cutting-edge performance or high specialization are impractical to manufacture in an array format. laser scanning rapidly deploys individual encoding masks as optically selected sub-regions larger aggregate patterns that are displayed via DMD. Pattern aggregation enhances SPI data acquisition rates to more than two orders of magnitude above the limitations of DMD-only modulation, while still retaining the frame size and flexibility of pattern display with DMDs. Meanwhile, a fast CS reconstruction algorithm, which is tightly coupled with the architecture of pattern deployment, is developed with full compatibility with parallel computing for real-time visualization.

A method and a system for imaging a transient event, the method comprising passively recording spatiotemporal projections of the transient event in an angular range from −45° to +45°; and processing the recorded spatiotemporal projections by compressed sensing tomographic image reconstruction to recover the transient event. The system comprises an imaging unit and a shearing unit for imaging a dynamic event to different positions, a detector that records data by spatially integrating over each pixel and temporally integrating; and a processing unit that reconstructs the dynamic event from said data by compressed sensing tomographic image reconstruction.

Real-time multidimensional terahertz imaging system and method, the method comprising method for imaging an object, comprising, in a laser pump line: patterning a laser pump beam with known patterns of a radiation beam and illuminating the object with the radiation beam; yielding a patterned pump beam; directing the patterned beam from the pump line and a laser probe beam from a laser probe line to a detection crystal; single-shot detection of the radiation beam waveform; and correlating the single-shot detection and the known patterns.