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We experimentally demonstrate a broadband, fabrication tolerant, CMOS compatible compact silicon waveguide taper (34.2 um) in silicon-on-insulator wire waveguides. The taper works on multi-mode interference along the length of the taper. A…

Applied Physics · Physics 2020-01-01 Purnima Sethi , Shankar Kumar Selvaraja

High-gain antennas are essential hardware devices, powering numerous daily applications, including distant point-to-point communications, safety radars, and many others. While a common approach to elevate gain is to enlarge an antenna…

Applied Physics · Physics 2023-04-20 Gilad Uziel , Dmytro Vovchuk , Andrey Machnev , Vjaceslavs Bobrovs , Pavel Ginzburg

Orbital angular momentum (OAM) based radio vortex wireless communications have received much attention recently because it can significantly increase the spectrum efficiency. The uniform circular array (UCA) is a simple antenna structure…

Signal Processing · Electrical Eng. & Systems 2018-09-14 Shanghua Gao , Wenchi Cheng , Wei Zhang , Hailin Zhang

The main objective of the present project is to explore the viability of an adaptive optics control system based exclusively on Field Programmable Gate Arrays (FPGAs), making strong use of their parallel processing capability. In an…

Instrumentation and Methods for Astrophysics · Physics 2018-07-03 Avinash Surendran , Mahesh P. Burse , A. N. Ramaprakash , Padmakar Parihar

Tunable narrowband spectral filters with high light throughput and wide dynamic range have remarkable applications such as in optical communications, optical spectroscopy and spectral imaging. However, a cost is usually associated with the…

Optics · Physics 2018-10-24 Ibrahim Abdulhalim

Deep subwavelength RF imaging with atomic Rydberg sensors has overcome fundamental limitations of traditional antennas and enabled ultra-wideband detection of omni-directional time varying fields all in a compact form factor. However, in…

Optical beam steering is an essential technology for free-space optical communication, reconfigurable optical networks and quantum information systems. Yet conventional steering methods either require bulky mechanical mechanisms, or rely on…

A single-order transmission diffraction grating based on dispersion engineered all-dielectric metasurfaces is proposed and its wavelength discriminating properties have been theoretically described and confirmed using numerical simulations.…

Optics · Physics 2016-08-24 Shulabh Gupta

One promising application of photonics to astronomical instrumentation is the miniaturization of near-infrared (NIR) spectrometers for large ground- and space-based astronomical telescopes. Here we present new results from our effort to…

Instrumentation and Methods for Astrophysics · Physics 2017-10-11 Pradip Gatkine , Sylvain Veilleux , Yiwen Hu , Joss Bland-Hawthorn , Mario Dagenais

The design, simulation and measurement of a beam steerable slotted waveguide antenna operating in X band are presented. The proposed beam steerable antenna consists of a standard rectangular waveguide (RWG) section with longitudinal slots…

Instrumentation and Detectors · Physics 2018-03-14 Amirhossein Ghasemi , Jean-Jacques Laurin

Using Optical Orthogonal Frequency Multiplexing (O-OFDM), variable bandwidth channels can be created in Elastic Optical Networks (EON). This allows the use of spectrum more efficiently by allocating integral multiple of basic bandwidth…

Networking and Internet Architecture · Computer Science 2022-12-09 Varsha Lohani , Anjali Sharma , Yatindra Nath Singh

We develop a single-layer waveguide surface grating structure to vertically couple near infrared (NIR) light at ~1.55 um wavelength from a large area (~100 um length scale) Si waveguide on a Silicon-On-Insulator (SOI) substrates to…

We propose two concepts for the significant improvement of surface current mapping with bistatic oceanographic High-Frequency Radars. These ameliorations pertain to the azimuthal processing of radar data with linear or quasi-linear antenna…

Signal Processing · Electrical Eng. & Systems 2020-05-22 Dylan Dumas , Charles-Antoine Guérin

Phase-sensitive detection is the essential projective measurement for measurement-based continuous-variable quantum information processing. The bandwidth of conventional electrical phase-sensitive detectors is up to several gigahertz, which…

Achieving broadband on-chip optical amplification spanning the visible and near-infrared (NIR) can enable diverse quantum sensing, metrology, and classical communication applications within a single unified device. However, conventional…

The remarkable frequency stability of resonant systems in the optical domain (optical cavities and atomic transitions) can be harnessed at frequency scales accessible by electronics using optical frequency division. This capability is…

Metallic gratings can be used as infrared filters, but their performance is often limited by bandwidth restrictions due to metallic losses. In this work, we propose a metallic groove-slit-groove (GSG) structure that overcomes these…

Optics · Physics 2024-12-02 Denis Langevin , Julien Jaeck , Riad Haïdar , Patrick Bouchon

This paper investigates multi-mode and orbital angular momentum (OAM) mode data transmission techniques by a using a circular antenna array, operating at 28 GHz. The classical mode excitation of the latter is modified such that in the…

Signal Processing · Electrical Eng. & Systems 2020-11-02 Stylianos D. Assimonis , M. Ali Babar Abbasi , Vincent Fusco

Pinching antennas is a novel flexible-antenna technology, which can be realized by employing small dielectric particles on a waveguide. The aim of this letter is to characterize the array gain achieved by pinching-antenna systems (PASS). A…

Signal Processing · Electrical Eng. & Systems 2025-04-15 Chongjun Ouyang , Zhaolin Wang , Yuanwei Liu , Zhiguo Ding

Due to the ultra-dense constellation, efficient beam coverage and interference mitigation are crucial to low-earth orbit (LEO) satellite communication systems, while the conventional directional antennas and fixed-position antenna (FPA)…

Information Theory · Computer Science 2024-04-25 Lipeng Zhu , Xiangyu Pi , Wenyan Ma , Zhenyu Xiao , Rui Zhang