- Tram Ho
A few years ago, Caltech researcher Lihong Wang developed the world’s fastest camera, capable of recording 10,000 billion images per second. It is so fast that it is possible to capture even the movement of light in a slow motion video.
But that doesn’t seem to be fast enough, because the camera hasn’t been able to capture things it doesn’t see. To solve this problem, Wang, a professor of medical engineering, has developed a new camera with a shutter speed of 1 trillion images per second, to capture transparent objects.
Structure diagram of pCUP camera system capable of recording 1,000 billion images per second.
Dubbed by Professor Wang as phase-sensitive compressed ultrafast photography: pCUP, this technology not only captures images of transparent objects, but also objects that have extremely short duration, such as shock waves, or maybe even signals as they travel through neurons.
According to Mr. Wang’s explanation, this system is a combination of a new imaging system and a high-speed imaging system that he developed previously based on an old technology – contrast phase microscopy ( phase contrast microscopy), which is designed to take better pictures of almost transparent objects such as cells, usually mostly water.
Invented nearly 100 years ago by Dutch physicist Frits Zernike, contrast phase microscopes work by taking advantage of light waves slowing down and speeding up as they enter different materials.
Images captured by pCUP camera show a laser pulse passing through crystal material.
For example, when a beam of light passes through a sheet of glass, it slows down upon contact with the glass and then speeds up again when released. These changes in speed will alter the cycle of light waves. Taking advantage of this and a number of other tricks, the researchers can distinguish light passing through the glass from light not passing through, even if the glass is transparent.
To record these super-fast images, Wang uses a technology called lossless encoding compressed ultrafast photography: LLE-CUP. Unlike most other super-fast photography technologies that record a series of images in succession while repeating the event, LLE-CUP only takes a single picture, capturing every movement from the time Capture points until completed. Because taking a single photo is much faster than taking many different photos, LLE-CUP is actually capable of capturing motion, for example the movement of light itself.
The shockwave image generated by laser projection in water is recorded by pCUP camera. This movement only lasts for 20 ns (nanoseconds, each nanosecond equals 1 billionth of a second).
In his research paper, Wang and his colleagues demonstrated the ability of pCUP by visualizing the shockwave propagating through water and a laser pulse when passing through a crystalline material.
Wang said that when the technology is completed, it will have applications in many different fields, including physics, biology and chemistry.
” When the signal travels through neurons, we can expect to see the nerve fibers expand for a moment. If we had a network of neurons, maybe we could see the communicate between them in real time . ” Mr. Wang said. Besides, because the temperature will change the contrast phase, this camera system ” can record images of the flare and spread in the combustion chamber of the engine .”
Refer to Phys
Source : Genk