- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Scattering of light from disordered photonic structures
摘要： We study theoretically and experimentally the scattering of light from ordered and disordered photonic structures. As an example, we consider a thin slab of a woodpile-type photonic crystal and introduce random fluctuations in the rod orientation, revealing a crossover from the Laue diffraction to the formation of speckle patterns. We observe a nontrivial interplay between order and disorder when the orientational disorder is added only in one direction of the square woodpile structure. Namely, ordered sets of rods produce disordered patterns and, vice versa, disordered sets of rods produce ordered patterns. We explain this effect theoretically and experimentally by the fact that light scatters only from the intersection points of different rods.
关键词： light scattering,Laue diffraction,speckle patterns,photonic structures,disorder
更新于2025-09-23 15:21:21
-
[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Wavelength Independent Image Classification through a Multimode Fiber using Deep Neural Networks
摘要： Deep Neural Networks (DNNs) have been increasingly implemented in different research fields or industrial applications. Large amounts of data are processed daily in order to extract useful information using machine learning techniques. Many research groups have shown impressive results on improving resolution in microscopy and quantitative phase retrieval by training DNNs on real datasets. Recently, recovery and reconstruction of images after they have propagated through multimode optical fibers (MMFs) have also been achieved using DNNs. When images propagate through MMFs they suffer severe scrambling because the information gets distributed among the different spatial modes that the fiber supports. Furthermore, since the fiber modes propagate with different velocities, the local information of the input decorrelates after a few millimeters along the MMF, thus resulting in the formation of a speckle pattern at the output. Recovery of information from such speckle patterns is of practical interest for integrating the MMFs for endoscopic applications in medicine or for signal recovery in telecommunications.
关键词： Wavelength Independence,Image Classification,Speckle Patterns,Multimode Optical Fibers,Deep Neural Networks
更新于2025-09-11 14:15:04
-
Space division multiplexing in standard multi-mode optical fibers based on speckle pattern classification
摘要： In optical communications the transmission bandwidth of single mode optical fibers is almost fully exploited. To further increase the capacity of a telecommunication link, multiplexing techniques can be applied across 5 physical dimensions: amplitude, quadrature, polarization, frequency and space, with all but the latter being nearly exhausted. We experimentally demonstrate the feasibility of an original space division multiplexing technique based on the classification of speckle patterns measured at the fiber’s output. By coupling multiple optical signals into a standard multimode optical fiber, speckle patterns arise at the fiber’s end facet. This is due to quasi-random interference between the excited modes of propagation. We show how these patterns depend on the parameters of the optical signal beams and the fiber length. Classification of the speckle patterns allows the detection of the independent signals: we can detect the state (i.e. on or off) of different beams that are multiplexed in the fiber. Our results show that the proposed space division multiplexing on standard multimode fibers is robust to mode-mixing and polarization scrambling effects.
关键词： space division multiplexing,mode-mixing,speckle patterns,polarization scrambling,optical communications,multimode optical fibers
更新于2025-09-11 14:15:04