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arXiv · 1505.01507

Control of coherent backscattering by breaking optical reciprocity

Y. Bromberg·B. Redding·S. M. Popoff·H. Cao
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Abstract

Reciprocity is a universal principle that has a profound impact on many areas of physics. A fundamental phenomenon in condensed-matter physics, optical physics and acoustics, arising from reciprocity, is the constructive interference of quantum or classical waves which propagate along time-reversed paths in disordered media, leading to, for example, weak localization and metal-insulator transition. Previous studies have shown that such coherent effects are suppressed when reciprocity is broken. Here we show that by breaking reciprocity in a controlled manner, we can tune, rather than simply suppress, these phenomena. In particular, we manipulate coherent backscattering of light, also known as weak localization. By utilizing a non-reciprocal magneto-optical effect, we control the interference between time-reversed paths inside a multimode fiber with strong mode mixing, and realize a continuous transition from the well-known peak to a dip in the backscattered intensity. Our results may open new possibilities for coherent control of classical and quantum waves in complex systems

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Y. Bromberg, B. Redding, S. M. Popoff, H. Cao. 2015-05-06. Control of coherent backscattering by breaking optical reciprocity. https://doi.org/10.1103/physreva.93.023826

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