Experimental observation of a fundamental length scale of waves in random media. Freak waves in the linear regime: a microwave study. Höhmann, R., Kuhl, U., Stöckmann, H.-J., Kaplan, L. Stability of branched flow from a quantum point contact. How branching can change the conductance of ballistic semiconductor devices. Unexpected features of branched flow through high-mobility two-dimensional electron gases. Imaging magnetic focusing of coherent electron waves. Coherent branched flow in a two-dimensional electron gas. Bringing branched flow to the field of optics, with its full arsenal of tools, opens the door to the investigation of a plethora of new ideas such as branched flow in nonlinear media, in curved space or in active systems with gain. Furthermore, the labile nature of soap films leads to a regime in which the branched flow of light interacts and affects the underlying disorder through radiation pressure and gradient force. We find that, counterintuitively, despite the random variations in the medium and the linear nature of the effect, the filaments remain collimated throughout their paths. We show that, as light propagates inside a thin soap membrane, smooth thickness variations in the film act as a correlated disordered potential, focusing the light into filaments that display the features of branched flow: scaling of the distance to the first branching point and the probability distribution of the intensity. Here we present the experimental observation of the branched flow of light. Branched flow may act as a trigger for the formation of extreme nonlinear events 14, 15, 16, 17 and as a channel through which energy is transmitted in a scattering medium 18. It was first observed for electrons 1, 2, 3, 4, 5, 6 and for microwave cavities 7, 8, and it is generally expected for waves with vastly different wavelengths, for example, branched flow has been suggested as a focusing mechanism for ocean waves 9, 10, 11, and was suggested to occur also in sound waves 12 and ultrarelativistic electrons in graphene 13. This fundamental wave phenomenon is known as branched flow. These rare night-sky phenomena are like Aurora Borealis in that they only appear under certain conditions.When waves propagate through a weak disordered potential with correlation length larger than the wavelength, they form channels (branches) of enhanced intensity that keep dividing as the waves propagate 1. But you might not have heard of light pillars. Just about everyone has heard of Aurora Borealis, the sky phenomena featured in the left half of this Northern Lights photo. What are light pillars? Alex poses in front of the dazzling phenomena. Instead, he says all he did was increase the exposure, brightness, colors, and shadows in Lightroom. He also shared that he’s new to post-processing and didn’t put the photo through Photoshop. In a Facebook post featuring the Northern Lights photo, Correia shared that it was captured in a single shot on a 4s. It’s a beautiful sight and one that Correia says he hasn’t edited very much. On the other, the lights from the city seem to jut up into the sky, like pillars of light. On one side, you can see the wavy lines that make up Aurora Borealis. The photo, which can be seen in full detail on Correia’s Instagram, shows both phenomena side by side. The new Northern Lights photo is indeed something unique. “I saw a great opportunity to take a unique picture,” he says (via PetaPixel). However, he says that when heading back to where he was staying, he noticed the lights of the city taking the shape of light pillars. Image source: Alexandre CorreiaĬorreia says that he was originally only focused on capturing the Northern Lights photo, as the lights were stronger in that direction. Two night sky phenomena caught side-by-side in new Northern Lights photo Photographer Alexandre Correia managed to capture both the Northern Lights and light pillars in one photo.
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