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Rotman lens is a true-time-delay beam forming network with parallel plate structure. Owing to its frequency- independency and wide-band operation, it has gained vast applications as feeding element of linear array antennas. However, the…

Information Theory · Computer Science 2016-12-30 Marjan Kashani , Ali Khaleghi

Development of novel radiation-absorbent materials and devices for millimetre and submillimetre astronomy instruments is a research area of high interest, and with substantial engineering challenges. Alongside low-profile structure and…

Instrumentation and Methods for Astrophysics · Physics 2023-02-10 Giampaolo Pisano , Christopher Dunscombe , Peter Hargrave , Alexey Shitvov , Carole Tucker

We use micromagnetic modelling to demonstrate the operation of graded index lenses designed to steer forward-volume magnetostatic spin waves by 90 and 180 degrees. The graded index profiles require the refractive index to diverge in the…

Applied Physics · Physics 2019-09-11 N. J. Whitehead , S. A. R. Horsley , T. G. Philbin , V. V. Kruglyak

Time has emerged as a new degree of freedom for metamaterials, promising new pathways in wave control. However, electromagnetism suffers from limitations in the modulation speed of material parameters. Here we argue that these limitations…

Mesoscale and Nanoscale Physics · Physics 2019-11-20 E. Galiffi , P. A. Huidobro , J. B. Pendry

Planar metamaterials with tailorable electromagnetic properties in the terahertz domain offer customized optics solutions that are needed for the development of imaging and spectroscopy systems. In particular, metamaterials carry the…

We demonstrate how the optical gradient force between two waveguides can be enhanced using transformation optics. A thin layer of double-negative or single-negative metamaterial can shrink the interwaveguide distance perceived by light,…

Strain-engineering of materials encompasses significant elastic deformation and leads to breaking of the lattice symmetry and as a consequence to the emergence of optical anisotropy. However, the capability to image and map local strain…

Optics · Physics 2024-07-26 Joan Sendra , Fabian Haake , Micha Calvo , Henning Galinski , Ralph Spolenak

Conventional optical lenses have been used to focus light from outside without disturbing the medium. The focused spot size is proportional to the focal distance in a conventional lens, resulting in a tradeoff between depth of penetration…

Graphene opens up for novel optoelectronic applications thanks to its high carrier mobility, ultra-large absorption bandwidth, and extremely fast material response. In particular, the opportunity to control optoelectronic properties through…

We report the design and characterization of a high performance integrated arbitrary filter from 1450 nm to 1640 nm. The filter's target spectrum is chosen to suppress the night-sky OH emission lines, which is critical for ground-based…

Instrumentation and Methods for Astrophysics · Physics 2020-06-02 Yi-Wen Hu , Shengjie Xie , Jiahao Zhan , Yang Zhang , Sylvain Veilleux , Mario Dagenais

This article concerns the design of antireflection structures which, placed on a photonic crystal surface, significantly diminish the fraction of energy lost to reflected waves. After a review of the classes of these structures proposed to…

Optics · Physics 2015-05-30 Wojciech Smigaj , Boris Gralak

Dielectric metasurfaces are structured thin films with thickness smaller than the wavelength that aim at replacing and enhancing conventional bulk optical components by structuring local resonances across an aperture. At visible and…

Graphene has generated exceptional interest as an optoelectronic material because its high carrier mobility and broadband absorption promise to make extremely fast and broadband electro-optic devices possible. Electro-optic graphene…

We show that a binary-staircase optical element can be engineered to exhibit an effective negative index of refraction, thereby expanding the range of optical properties theoretically available for future optoelectronic devices. The…

Optics offers unique opportunities for reducing energy in information processing and communications while resolving the problem of interconnect bandwidth density inside machines. Such energy dissipation overall is now at environmentally…

Optics · Physics 2017-01-30 David A. B. Miller

Integrated optical devices able to control light matter interactions on the nanoscale have attracted the attention of the scientific community in recent years. However, most of these devices are based on silicon waveguides, limiting their…

Manipulating underwater pressure waves is crucial for marine exploration, as electromagnetic signals are strongly absorbed in water. However, the multi-path phenomenon complicates the accurate capture of acoustic waves by receivers.…

Optimization and Control · Mathematics 2025-01-03 Sebastiano Cominelli , Francesco Braghin

Metasurfaces provide a compact, flexible, and reliable solution for controlling the wavefront of light. In imaging systems, micro-lens arrays are integrated with pixel matrices to reduce optical crosstalk, enhance photon collection…

Metasurfaces with local phase tuning by subwavelength elements promise unprecedented possibilities for ultra-thin and multifunctional optical devices, in which geometric phase design is widely used due to its resonant-free and large…

The use of Immersed Gratings offers advantages for both space- and ground-based spectrographs. As diffraction takes place inside the high-index medium, the optical path difference and angular dispersion are boosted proportionally, thereby…

Instrumentation and Methods for Astrophysics · Physics 2015-10-16 Michiel Rodenhuis , Paul J. J. Tol , Tonny H. M. Coppens , Phillip P. Laubert , Aaldert H. van Amerongen