Proceedings

EPJ D Highlight - Bringing the chaos in light sources under control

Experimental reconstruction of the phase portrait of the quantum dot light emitting diode using the embedding technique.

Study investigates how best to stabilise the output of quantum dot LEDs

Noise is an issue in optical telecommunications. And findings means of controlling noise is key to physicists investigating light-emitting diodes or lasers. Now, an Italo-Iraqi team has worked on a particular type of light source, called the quantum dot light-emitting diode (QDLED). In a study published in EPJ D, Kais Al Namee from the National Institute of Optics, in Florence, Italy and colleagues, demonstrate that modulating bias current of the QDLED could lead to countering the noise. This, in turn, leads to stabilising such light sources, making them better suited for optical telecommunications.

Most light sources exhibit fluctuations due to the quantum nature of the process underlying the emission of light. However, experiments show that these fluctuations - often described as quantum noise - are inherently chaotic and subject to oscillations, dubbed mixed mode oscillations. The authors have developed a theoretical model, which they show is able to reproduce the chaotic and oscillating phenomena observed experimentally. This can help them understand the nature of such phenomena.

They found that spiking competition of quantum dots in the part of the diode that emits lights enhances the way in which the diode receives its own self-feedback in terms of the light being emitted and it also has an effect on the impact of noise perturbation. They also show that the dynamics of these fluctuations are completely determined by the variation of the injecting bias current feeding into the QDLED.

As a result, Al Naimee and colleagues realised that fluctuations can be brought under control by changing the bias current. The next step in their research will involve focusing on synchronisation phenomena in QDLED arrays for using this source in optical telecommunications. Other potential applications could include quantum dot-enhanced LED-backlighting of LCD televisions.

This was our first experience of publishing with EPJ Web of Conferences. We contacted the publisher in the middle of September, just one month prior to the Conference, but everything went through smoothly. We have had published MNPS Proceedings with different publishers in the past, and would like to tell that the EPJ Web of Conferences team was probably the best, very quick, helpful and interactive. Typically, we were getting responses from EPJ Web of Conferences team within less than an hour and have had help at every production stage.
We are very thankful to Solange Guenot, Web of Conferences Publishing Editor, and Isabelle Houlbert, Web of Conferences Production Editor, for their support. These ladies are top-level professionals, who made a great contribution to the success of this issue. We are fully satisfied with the publication of the Conference Proceedings and are looking forward to further cooperation. The publication was very fast, easy and of high quality. My colleagues and I strongly recommend EPJ Web of Conferences to anyone, who is interested in quick high-quality publication of conference proceedings.

On behalf of the Organizing and Program Committees and Editorial Team of MNPS-2019, Dr. Alexey B. Nadykto, Moscow State Technological University “STANKIN”, Moscow, Russia. EPJ Web of Conferences vol. 224 (2019)

ISSN: 2100-014X (Electronic Edition)

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