Capable of Observing Waveforms of Light without Distortion
The Korea Atomic Energy Research Institute announced on Dec. 21 that it has developed the most advanced ultrafast oscilloscope. “The oscilloscope has a bandwidth of 1 terahertz and a sampling rate of 75.7 tera sampling per second and is capable of observing waveforms of light without distortion,” it said.
In a general oscilloscope, the trajectory of an electron beam passing between two electrodes and bent by an electromagnetic wave as an object of measurement is measured continuously. The ultrafast oscilloscope developed by the institute has a completely different structure. In this structure, an electromagnetic wave passes through the narrow gap between metal plates and a horizontal bar-shaped electron beam records it at once like stamping.
In this case, a thinner electron beam is capable of observing the electromagnetic wave more precisely and covering a wider frequency range for observation. This means the degree of electron beam compression matters. Given the nature of electrons, those in a narrow space generate a repulsive force and a thin electron beam is unlikely to be maintained in the presence of the force. The institute offset the repulsive force of electrons by accelerating an electron beam to the speed of light in order to solve this problem. As a result, the thickness of the beam could be reduced to 7.5 micrometers and an electromagnetic waveform vibrating at a frequency of 1 terahertz could be measured.
“Real-time electromagnetic waveform observation on a petahertz level is expected to become possible based on this attainment,” the institute explained, adding, “Data collection of peta sampling per second is possible according to our experiment and we will focus on electron beam compression to hundreds of nanometers.” Details of the research are available in the Nature Communications journal.