The study released narrowband light sources in media where electromagnetic radiation would not normally be feasible. It makes for a robust tool for the researchers that allow them to comprehend the intricacies of how substances or even biological molecules function under distinct conditions, which has a major impact on lives of people through the development of novel products and medical treatments.
The research involved the scientists from the Ulsan National Institute of Science and Technology and the Gwangju Institute of Science and Technology, South Korea. Lecturer Dino Jaroszynski of the Strathclyde’s Department of Physics headed the study. He confirmed that ‘coherent light sources like the lasers have numerous uses from communication to probing the structure of the entire matter. The simplest source of coherent electromagnetic radiation is a moving electrical current in an antenna.
However, there are numerous other devices that are based on the basic laws of physics, like the free-electron laser that produced coherent X-ray radiation or magnetrons identified in microwave ovens. “Our research has revealed that some common media with amazing optical features can be taken benefit of if we imbed, or bury a moving current source in them. Media such as plasma, photonic structures and semiconductors have a ‘cut-off’, where propagation of electromagnetic radiation with frequencies less than the ‘cut-off; frequency is not feasible, we noticed that the radiation impedance is enhanced at the cut-off.
“One result of this is that for a broadband source of current immersed in such sort of dispersive medium, the cut-off frequency mode is selectively enhanced due to the Ohm’s Law, leading to the narrow bandwidth emission. What is curious is that the new physics should be still hidden in the conventional cut-off behaviour, in our study, we uncovered a hidden face of the cut-off and realised a novel paradigm of narrowband light sources in the media that would not usually enable electromagnetic radiation to propagate. This is a significantly simple theory based on straightforward physics theory that seems to have been overlooked.
“It is an exciting theoretical discovery that comes out of a highly fruitful cross-continental association. It reveals that we must always keep an open mind and question even very simple assumptions. We expect to illustrate this procedure at the Strathclyde-based Scottish Centre for the application of plasma-based accelerators.”
The biggest challenge, right now, is preparing high power sources of electromagnetic radiation monochromatic. This is often performed by making the oscillating current narrowband or filtering the spectrum that is highly difficult. It is complicated and quite be expensive to reduce the overall bandwidth of a current source while maintaining or enhancing its radiated power.
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