Post #5092

Engines of light: New study suggests we could increase useful energy obtained from sunlight Physicists from Trinity College Dublin believe new insights into the behavior of light may offer a new means of solving one of science's oldest challenges—how to turn heat into useful energy. Their theoretical leap forwards, which will now be tested in the lab, could influence the development of specialized devices that would ultimately increase the amount of energy we can capture from sunlight (and lamps and LEDs) and then repurpose to perform useful tasks. The work has just been published in the journal, Physical Review A. When photons (particles of light) are trapped in microscopic optical devices, they can undergo a form of condensation, where they behave collectively rather than as independent particles. In practice, this concentrates light energy into a small, intense beam of a single very pure color, similar to the output of a laser. This phenomenon has been seen in experiments, but only when the energy input is already in the concentrated form provided by a laser. Now though, thanks to the new theoretical analysis, the physicists think it can be achieved using input energy in a diffused form, like that readily provided by sunlight, lamps, or LEDs. Paul Eastham, Naughton Associate Professor, School of Physics, Trinity, is the senior author of the study. He said, "We modeled the behavior of devices which trap light in a small region of space and found that this behavior is related to the general properties of heat engines: machines that convert disorganized energy, which we physicists call 'heat,' into a useful form, which we call 'work.'" "In this way, the same laws that limit steam engines and power plants determine whether photons condense or not. Beyond the conceptual appeal of this work, we believe it could influence the development of optical devices which rely on channeling the flow of light energy at the quantum level, from solar cells to microscopic engines powered by radiation." Source:Phys.org @EverythingScience