Tootfinder

High-reflectivity homoepitaxial distributed Bragg reflectors for photonic applications
Helena Janowska, Anna Musia{\l}, Grzegorz S\k{e}k
https://arxiv.org/abs/2507.20211 https:/…

High-reflectivity homoepitaxial distributed Bragg reflectors for photonic applications
Distributed Bragg reflectors (DBRs) are one of the basic photonic structures used to define microcavities for fundamental light-matter coupling studies, as well as to optimize performance of optoelectronic and photonic devices, e.g., lasers or non-classical light sources. The reflectivity of these structures depends critically on the refractive index contrast between the two quarter-wavelength thick layers constituting the DBR. At the same time, epitaxial fabrication process limits the choice o…

On the Compromise Between Performance and Efficiency in RIS-aided Communication Systems
P. H. C. de Souza (National Institute of Telecommunications - Inatel), M. Khazaee (National Institute of Telecommunications - Inatel), L. L. Mendes (National Institute of Telecommunications - Inatel)
https://arxiv.org/abs/2508.15599

On the Compromise Between Performance and Efficiency in RIS-aided Communication Systems
The reconfigurable intelligent surface (RIS) technology for metasurfaces is ushering in a new paradigm for wireless communication systems. It provides an accessible way for controlling the interaction between electromagnetic waves with the propagation medium. One particularly important aspect is the configuration of the RIS elements or reflectors. Simply stated, the objective of the RIS configuration is to choose the optimum phase-shift combination that maximizes the channel capacity. Recently,…

The Trip to ZigBee Backscatter across a Decade, a Systematic Review
Yang Liu
https://arxiv.org/abs/2506.13822 https://arxiv.org/pdf/2…

The Trip to ZigBee Backscatter across a Decade, a Systematic Review
The field of backscatter communication has undergone a profound transformation, evolving from a niche technology for radio-frequency identification (RFID) into a sophisticated paradigm poised to enable a truly battery-free Internet of Things (IoT). This evolution is built upon a deepening understanding of the fundamental principles governing these ultra-low-power links. Modern backscatter systems are no longer simple reflectors of continuous waves but are increasingly designed to interact with …

Measurement of the Primary Beam of the Tianlai Cylindrical Antenna Using an Unmanned Aerial Vehicle
Jixia Li, Nanben Suo, Shenzhe Xu, Shijie Sun, Shifan Zuo, Yougang Wang, Fengquan Wu, Juyong Zhang, Peter Timbie, Reza Ansari, Albert Stebbins, Xuelei Chen
https://arxiv.org/abs/2508.01413

Measurement of the Primary Beam of the Tianlai Cylindrical Antenna Using an Unmanned Aerial Vehicle
The Tianlai Cylinder Pathfinder Array consists of three adjacent cylindrical reflectors fixed on the ground, each 40 meters long and 15 meters wide, with the cylinder axis oriented along the North-South (N-S)direction. Dual linear polarisation feeds are distributed along the focus line, parallel to the cylinder axis. Measurement of the primary beam profile of these cylindrical reflectors is difficult, as they are too large to be placed in an anechoic chamber. While the beam profile along the Ea…

Single photon emission from lithographically-positioned engineered nanodiamonds for cryogenic applications
Vivekanand Tiwari, Zhaojin Liu, Hao-Cheng Weng, Krishna C Balram, John G Rarity, Soumen Mandal, Oliver A Williams, Gavin W Morley, Joe A Smith
https://arxiv.org/abs/2508.06424

Single photon emission from lithographically-positioned engineered nanodiamonds for cryogenic applications
Nitrogen-vacancy centres in nanodiamonds (NDs) provide a promising resource for quantum photonic systems. However, developing a technology beyond proof-of-principle physics requires optimally engineering its component parts. In this work, we present a hybrid materials platform by photolithographically positioning ball-milled isotopically-enriched NDs on broadband metal reflectors. The structure enhances the photonic collection efficiency, enabling cryogenic characterisation despite the limited …

MudiNet: Task-guided Disentangled Representation Learning for 5G Indoor Multipath-assisted Positioning
Ye Tian, Xueting Xu, Ao Peng
https://arxiv.org/abs/2506.04024

MudiNet: Task-guided Disentangled Representation Learning for 5G Indoor Multipath-assisted Positioning
In the fifth-generation communication system (5G), multipath-assisted positioning (MAP) has emerged as a promising approach. With the enhancement of signal resolution, multipath component (MPC) are no longer regarded as noise but rather as valuable information that can contribute to positioning. However, existing research often treats reflective surfaces as ideal reflectors, while being powerless in the face of indistinguishable multipath caused by diffuse reflectors. This study approaches diff…

Design of a three-dimensional parallel-to-point imaging system based on inverse methods
Sanjana Verma, Lisa Kusch, Koondanibha Mitra, Martijn J. H. Anthonissen, Jan H. M. ten Thije Boonkkamp, Wilbert L. IJzerman
https://arxiv.org/abs/2507.02507

Design of a three-dimensional parallel-to-point imaging system based on inverse methods
We present an inverse method for designing a three-dimensional imaging system comprising of freeform optical surfaces. We impose an imaging condition on the optical map and combine it with the law of conservation of energy to conclude that the ratio of energy distributions at the source and target of an imaging system must be constant. A mathematical model for the design of a parallel-to-point system consisting of two freeform reflectors is presented. A Schwarzschild telescope, a classical desi…

Hardware Limitations and Optimization Approach in 1-Bit RIS Design at 28 GHz
Hossein Rezaei, Mehmet Emin Arslan, George Yammine, Niels Neumann, Norman Franchi
https://arxiv.org/abs/2506.08930

Hardware Limitations and Optimization Approach in 1-Bit RIS Design at 28 GHz
Reconfigurable intelligent surfaces (RIS) have emerged as a transformative technology for electromagnetic (EM) wave manipulation, offering unprecedented control over wave reflections compared to traditional metallic reflectors. By utilizing an array of tunable elements, RIS can steer and shape electromagnetic waves to enhance signal quality in wireless communication and radar systems. However, practical implementations face significant challenges due to hardware limitations and phase quantizati…