- Post By : Kumar Jeetendra
- Source: INRS
- Date: 08 Oct,2020
Compressed ultrafast photography (CUP) captures the whole process in real time and unparalleled resolution with only one click. The spatial and temporal information is compressed into a picture and then, with a reconstruction algorithm, it is converted into a movie.
Developing a compact instrument for UV
Until now, this technique was limited to visible and near-infrared wavelengths, and thus to a particular category of physical events. “Many phenomena that occur on very short time scales also occur on a really small spatial scale. To see them, you need to sense shorter wavelengths.
To document in this new selection of wavelengths and to develop the technique to a user-friendly item, researchers designed a compact UV-CUP system with Christian?Yves Côté of Axis Photonique Inc. via an academia-industry collaboration.
The new system includes a patterned photocathode, which can be used to simultaneously detect and encode”black light”. “Like a typical camera, our technology is passive. It doesn’t produce light; it receives it. Therefore, our photocathode had to be sensitive to the photons emitted as UV light.
This design makes our technique a stand-alone system that can be easily integrated into various experimental programs,” says Jinyang Liang, who has been contributing to the growth of CUP since his postdoctorate.
Rather than solve the reconstruction problem as a lump, the algorithm divides the reconstruction into smaller problems that it tackles individually.”-Jinyang Liang, Study Lead and Professor, INRS
Liang worked with François Légaré, also an INRS professor, to create and take pictures of UV pulses at the Advanced Laser Light Source (ALLS) lab. “The outstanding research environment in the Énergie Matériaux Télécommunications Research Centre of INRS is very helpful. It’s so much more efficient when all essential design, manufacturing, and characterization capabilities can be found in the same building.”
“Taking the picture is just the first half of this job,” says Jinyang Liang. “It also has to be rebuilt.” To do this, the researchers developed a new algorithm, more efficient than conventional algorithms, via their collaboration with Boston University. Its strength comes from a branch of tasks.
It produces videos using 1500 frames in big format.
The apparatus developed through this international collaboration will be sent to the study laboratory SOLEIL Synchrotron in France to visualize physical phenomena. It might capture laser-plasma generation, a phenomenon that is essential for deducing certain properties of substances, and UV fluorescence, which can be important in medical imaging to identify biomarkers linked to ailments.
Lai, Y., et al. (2020) Single‐Shot Ultraviolet Compressed Ultrafast Photography. Laser & Photonics Reviews. doi.org/10.1002/lpor.202000122.