- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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[IEEE 2018 International Symposium on Networks, Computers and Communications (ISNCC) - Rome (2018.6.19-2018.6.21)] 2018 International Symposium on Networks, Computers and Communications (ISNCC) - Design of a Photoconductive Antenna for Pulsed-Terahertz Spectroscopy with Polarization Diversity
摘要： In the present paper, a photoconductive antenna is designed to work as both pulse-terahertz emitter and receiver. The proposed two-port antenna benefits from polarization diversity with high sensitivity of polarization detection. The antenna electrodes consist of three arms and two gaps that can be excited by laser illumination. An 800 nm wavelength laser beam with output power of 80 mW, 100 MHz repetition rate, and 100 fs laser pulse duration is considered as optical excitation. Each port stimulates a pulse that its polarization is orthogonal to that of the other one according to their arrangement. Along with GaAs as photoconductive substrate beneath the antenna electrodes, an anti-reflection coating of Taconic RF-35 is used for depreciating unwanted terahertz echoes. The simulated results clarify that the proposed antenna shows polarization diversity and also, proper broadband behavior.
关键词： spectroscopy,polarization diversity,pulsed terahertz,photoconductive antenna
更新于2025-09-23 15:23:52
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Broadband simultaneously RHCP-LHCP radiating microstrip fed rectangular slot antenna for polarization diversity applications
摘要： In this article, for the first time, an antenna that can radiate LHCP and RHCP waves simultaneously is presented. The antenna enables simultaneous transmission of both right-handed (RH) and left-handed (LH) circular polarized (CP) waves separately over an elevation range from -45 to 45 degrees from the zenith. The simultaneous radiation of dual sense CP in the different spatial directions enables the antenna to act as polarization diversity transmitter. The mechanism of virtual sequential rotation of magnetic currents inside the different parts of the slot, excited with uniform phase fields results in dual CP generation. The uniform phase orthogonal fields are generated in the different parts of the slot essentially by exciting the full wavelength rectangular slot loaded with grounded stubs, symmetrically, with a shorted microstrip line. The final design of the slot antenna arrived with a rigorous parametric study on different dimensional parameters of slot and grounded stub. The measured impedance bandwidth of 22.5% centered around 7 GHz and axial ratio bandwidth of 19% is achieved. An overlapping bandwidth of 17% is achieved where both matching and AR are very good. The measured isolation between the RHCP and LHCP in the above-mentioned elevation ranges is maintained above 10 dB. The simulated and experimental results are matching very well.
关键词： right-handed CP,magnetic currents,Mobile satellite communications,axial ratio,rectangular slot,polarization diversity,left-handed CP,simultaneous dual CP
更新于2025-09-23 15:23:52
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Polarization-fading-free distributed acoustic sensing system
摘要： A fiber-optic distributed acoustic sensing system based on polarization diversity technology is proposed and demonstrated. Without the polarization fading phenomenon, the false alarm rate is considerably reduced, making the system much practicable for real applications. The technology can't eliminate phase noise caused by polarization disturbance of transmission fiber. In order to solve the above problems, this paper adopts the polarization diversity method in the system to eliminate the polarization fading phenomenon, which is experimentally demonstrated to greatly reduce the missing and false alarm rate of the DAS system, and therefore greatly improved the system practicability.
关键词： polarization diversity,polarization fading,distributed acoustic sensing,false alarm
更新于2025-09-16 10:30:52
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[IEEE 2018 Photonics in Switching and Computing (PSC) - Limassol, Cyprus (2018.9.19-2018.9.21)] 2018 Photonics in Switching and Computing (PSC) - Polarization Diversity Circuit Using Photonic Crystal Waveplates for 1.2-μm Quantum Dot Semiconductor Optical Amplifiers
摘要： Silica-based polarization diversity circuit for QD-SOA operating in T-band was fabricated. By connecting polarization diversity the polarization dependent gain of less than 0.8 dB and the optical gain of 3.2 dB were achieved.
关键词： Semiconductor optical amplifier,Polarization diversity,Quantum dot
更新于2025-09-16 10:30:52
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Polarization diversity circuit based on silica waveguides and photonic crystal waveplates for a 4??4 silicon optical switch
摘要： We propose a compact polarization diversity circuit for a silicon waveguide device. It consists of silica waveguides and photonic crystal waveplates, and can convert input light with various polarization states into two output light signals with the same polarization. Setting these circuits at the front and rear of two silicon optical switches, the polarization dependence in the switch can be dramatically suppressed. We fabricated polarization diversity circuits for a 4×4 silicon optical switch and realized a polarization insensitive 4×4 optical switch. The polarization dependent loss was reduced to 1.1 dB and the polarization dependent crosstalk was less than ?17 dB.
关键词： silicon photonics,polarization diversity circuit,optical switch
更新于2025-09-16 10:30:52
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[IEEE 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Paris, France (2018.7.8-2018.7.13)] 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Design of Optical Current Sensor for Intelligent State Detection in Distribution Network
摘要： We propose a fiber optical current sensor (FOCS) based on polarization diversity for intelligent state detection in distribution network. A real-time state of polarization measurement is employed to eliminate the degradation of the Faraday effect. In experiment, a maximally 2 times higher sensitivity was achieved compared with that of the conventional one. The proposed method exhibits good immunity to the random variation of birefringence and the real rotation angle due to the Faraday effect can be accurately detected. Besides, the measurement bandwidth and accuracy of proposed FOCS are considerable.
关键词： fiber current sensor,smart grid,polarization diversity detection
更新于2025-09-10 09:29:36
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Performance comparison of combining algorithms for polarization-diversity receiving in phase-sensitive OTDR
摘要： We investigate three different combining algorithms for polarization-diversity receiving in phase-sensitive optical time-domain reflectometry (φ-OTDR) system. The algorithms are equal gain combining(EGC), selective combining(SC) and max-ratio combining(MRC). We compare the performance of the three combining algorithms in three aspects, which are the SNR of the locating signal, the SNR of the recovered vibration signal and the computation cost of the algorithms. The results show that the SC algorithm has a poor locating performance and is unsuitable for locating of the system. The EGC algorithm has the lowest complexity and general locating performance, which can be applied in real-time locating of external vibration. The performance of MRC algorithm is optimal, which is a promising tool in the high SNR intrusion location system. The proper combining algorithms we chosen will contribute to achieving optimal performance and optimal resource allocation of the φ-OTDR system.
关键词： Distributed optical fiber sensor,polarization-diversity combining algorithms,φ-OTDR
更新于2025-09-10 09:29:36
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Design and investigation of a dual-layer grating coupler for efficient vertical fiber-chip coupling
摘要： A novel dual-layer grating coupler was designed for efficient vertical coupling between a single-mode fiber and silicon nanowires, with characteristics of polarization diversity and both wavelength bands of 1.3 and 1.55 μm. Theoretical analysis and two-dimensional finite-difference time-domain simulations were applied to verify the performance of the design. Optimized results show that the coupling efficiencies of a dual-port output of 41% (?3.87 dB) for transverse-electric polarization at 1.56 μm, 32.88% (?4.83 dB) for transverse-magnetic (TM) polarization at 1.58 μm, and 27.06% (?5.68 dB) for TM polarization at 1.32 μm can be achieved. Dual-layer Fabry–Perot resonance was also investigated for high coupling efficiency.
关键词： silicon nanowires,dual-layer grating coupler,vertical fiber-chip coupling,polarization diversity,wavelength bands
更新于2025-09-04 15:30:14