Results 1 to 10 of about 27,131 (169)

Numerical Investigation of Natural Light Transmission Through Fiber Optics

Energies
Fiber optics is a cutting-edge technology with boundless potential for transmitting natural light inside buildings. Imaging Solar concentrators are very efficient in focusing light within the approximate numerical aperture of fiber optics.
Taher Maatallah, Mussad Alzahrani, Ahmad Almatar, Faisal Wahab, Sajid Ali   +4 more
doaj   +3 more sources

Detection of Low RCS Unmanned Air Systems Using K-Band Continuous Wave Doppler Radar

Journal of Electrical and Computer Engineering, 2023
UASs (Unmanned Air Systems) are universally used in many activities, spanning from leisure-commercial to military applications. Accordingly, as the number of UASs operating in the sky increases, so does the need to detect and identify them, in order to ...
Alexandros Kyritsis, Rodoula Makri, Nikolaos Uzunoglu   +2 more
doaj   +1 more source

Stabilized Long-Distance Superluminal Propagation Based on Polarization-Matched Low-Noise Brillouin Lasing Resonance

IEEE Photonics Journal, 2022
This paper comprehensively investigated noise characteristics of superluminal propagation based on low-noise single-frequency Brillouin lasing oscillation with the aid of a population inversion dynamic grating.
Liang Zhang, Zhelan Xiao, Zenghuan Qiu, Jilin Zhang, Li Zhan, Fufei Pang, Tingyun Wang   +6 more
doaj   +1 more source

Deep learning–based vortex decomposition and switching based on fiber vector eigenmodes

Nanophotonics, 2023
Structured optical fields, such as cylindrical vector (CV) and orbital angular momentum (OAM) modes, have attracted considerable attention due to their polarization singularities and helical phase wavefront structure.
Hou Mengdie, Xu Mengjun, Xu Jiangtao, Lu Jiafeng, An Yi, Huang Liangjin, Zeng Xianglong, Pang Fufei, Li Jun, Yi Lilin   +9 more
doaj   +1 more source

A Highly-Sensitive Temperature-Sensor Based on a Microfiber Knot-Resonator Packaged in Polydimethylsiloxane

IEEE Photonics Journal, 2021
In this paper, a microfiber knot resonator (MKR) was encapsulated in polydimethylsiloxane (PDMS), and its capability to sense temperature was experimentally evaluated.
Hongtao Dang, Mingshu Chen, Jin Li
doaj   +1 more source

Small UAS Online Audio DOA Estimation and Real-Time Identification Using Machine Learning

Sensors, 2022
The wide range of unmanned aerial system (UAS) applications has led to a substantial increase in their numbers, giving rise to a whole new area of systems aiming at detecting and/or mitigating their potentially unauthorized activities.
Alexandros Kyritsis, Rodoula Makri, Nikolaos Uzunoglu   +2 more
doaj   +1 more source

A Fiber-Optic Accelerometer Based on Extrinsic Fabry-Perot Interference for Low Frequency Micro-Vibration Measurement

IEEE Photonics Journal, 2022
A fiber-optic accelerometer based on extrinsic Fabry-Perot interferometer (EFPI) is reported. The sensor adopts flywheel diaphragm structure as a sensitive element, where the mass block is bonded in the center, while the beam of the flywheel acts as a ...
Peng Zhang, Shuang Wang, Junfeng Jiang, Zhiyuan Li, Haokun Yang, Tiegen Liu   +5 more
doaj   +1 more source

A MMIC QPSK Modulator

Active and Passive Electronic Components, 2002
In this paper a MMIC QPSK modulator is described. The bit rate of the baseband signal is 155 Mbits/sec, while the frequency of the carrier is fLO=10 GHz . The modulation is performed directly at the RF band and therefore an IF stage is not necessary. The
Petros S. Tsenes, Giorgos E. Stratakos, S. Nikolaos, K. Uzunoglu   +3 more
doaj   +1 more source

Fiber Optic Sensors for Harsh and High Radiation Environments in Aerospace Applications

Sensors, 2023
In the upcoming space revolutions aiming at the implementation of automated, smart, and self-aware crewless vehicles and reusable spacecraft, sensors play a significant role in the control systems.
Alberto Rovera, Alexandru Tancau, Nadia Boetti, Matteo D. L. Dalla Vedova, Paolo Maggiore, Davide Janner   +5 more
doaj   +1 more source

X-Band MMIC Active Mixers

Active and Passive Electronic Components, 2002
In this paper two active MMIC mixers for RF front-end applications are described. A down-converter that converts an RF signal (fRF=10.45 GHz) into an IF signal (fIF=0.95 GHz) using an LO signal (fLO=9.5 GHz) and an up-converter that performs the ...
Ptros S. Tsenes, Giorgos E. Stratakos, Nikolaos K. Uzunoglu   +2 more
doaj   +1 more source