American scientists have improved the world's fastest camera in order to capture transparent objects and invisible processes such as shock waves or laser pulses. The description is in the journal Science Advances.
Just over a year ago, California Institute of Technology professor Lihong Wang developed the world's fastest camera - a device capable of capturing 10 trillion pictures per second. It's so fast that it can even show the movement of light in slow motion. But this device was not suitable for capturing transparent objects or processes occurring in transparent environments.
Now Lihong Wang and his colleagues have unveiled a new development that combines an ultra-fast camera capable of producing one trillion images per second and a phase contrast microscope. The device captures ultra-fast images of transparent objects and even invisible phenomena such as shock waves or laser pulses.
Phase contrast microscopy was developed almost 100 years ago by the Dutch physicist Fritz Zernike to enable the visualization of transparent objects, such as cells, which are mostly water. The method is based on the fact that light waves are slowed down or accelerated when passing through various materials. For example, if a ray of light passes through a piece of glass, it slows down as it enters the glass and then accelerates again as it exits. These changes in speed are reflected in the travel time of the waves. With the help of some optical techniques, it is possible to distinguish light that has passed through glass from light that has not passed through it, and the glass becomes visible to instruments.
“We have adapted standard phase contrast microscopy to provide very fast imaging that allows us to display ultra-fast phenomena in transparent materials,” Lihun Wang said in a press release from the institute.
Ultra-fast rendering is achieved through Wang's compressed, ultra-fast, lossless LLE-CUP encoding technology. Unlike most other ultra-fast video technologies that take a series of images sequentially, the LLE-CUP system takes a single shot, capturing all movement from start to finish.
Wang called the new technology phase-sensitive compressed ultrafast photography. To show the capabilities of the device, scientists filmed the propagation of a shock wave in an aqueous medium and a laser pulse in a crystalline material.
According to the researcher, the technology is still at an early stage of development, but over time it will be able to find applications in many areas of physics, chemistry and biology. With some refinement, it will be possible to record on video even how the signal passes through the neurons. Small extensions of nerve fibers that occur during the passage of signals will allow you to see the interaction in the network of neurons.
"We hope to see a slight expansion of nerve fibers as signals pass through neurons. And in a neural network, we may be able to see their connection in real time," says the scientist. In addition, he said, since temperature is known to change phase contrast, the system "is able to depict how a flame front propagates in a combustion chamber."