Physicists have developed a new type of detector with which you can precisely determine the oscillation profile of light waves.
Light is hard to hold. Light waves travel at speeds of nearly 300,000 km / s, and wave faces vibrate several hundred trillion times in the same interval. In the case of visible light, the physical distance between successive light wave peaks is less than 1 micron and the peaks are separated by less than 3 million billion seconds (<3 femtoseconds).
In order to work with light, you must control it, and this requires proper knowledge of its behavior. It may even be necessary to know the exact position of the ridge or valley of light waves at a certain point in time.
With such an impulse, which only includes a few wave vibrations, the behavior of the molecule and its atomic components can be examined, and the new detector is an invaluable tool in this context. Ultrashort laser pulses allow scientists to study dynamic processes at the molecular and even subatomic levels.
With the help of the train of these impulses, it is possible to first excite the target particle and then record the reaction in real time. However, in an intensive light field, it is important to know the exact shape of the pulse wave. Because the ends of the light fields oscillate (the carrier) and that the pulses of the pulses can shift relative to each other between different laser pulses, it is important to know the exact wave shape of each pulse.
Now the team has made a decisive breakthrough in the characteristics of light waves. Your new detector allows you to specify “phases” ie. exact position of the peak of various oscillation cycles in each pulse at a repetition rate of 10,000 pulses per second.
For this purpose, the group produces circularly polarized laser pulses, in which the orientation of the optical field propagates clockwise and then focuses the pulses rotating in the surrounding air.
The interaction between the pulse and the molecules in the air produces a brief electrical surge, whose direction depends on the position of the tip of the light wave.
The researchers analyzed the exact direction of the current pulse and were able to extract the phase transfer of the carrier shell and thus reconstruct the light waveform.
When applied to the latest sources of ultra-fast lasers, this new waveform analysis can pave the way for technological breakthroughs and provide new insights about the behavior of elementary particles “in the fast lane”.