scholarly journals Multi-Addressed Fiber Bragg Structures for Microwave-Photonic Sensor Systems

Sensors ◽  
2020 ◽  
Vol 20 (9) ◽  
pp. 2693 ◽  
Author(s):  
Oleg Morozov ◽  
Airat Sakhabutdinov ◽  
Vladimir Anfinogentov ◽  
Rinat Misbakhov ◽  
Artem Kuznetsov ◽  
...  
Keyword(s):  
Frequency Shift ◽  
Microwave Frequency ◽  
Optical Signal ◽  
Electrical Signal ◽  
Infrared Range ◽  
Electromagnetic Spectrum ◽  
Sensor Systems ◽  
Central Frequency ◽  
Bragg Structure ◽  
Microwave Photonic

The new theory and technique of Multi-Addressed Fiber Bragg Structure (MAFBS) usage in Microwave Photonics Sensor Systems (MPSS) is presented. This theory is the logical evolution of the theory of Addressed Fiber Bragg Structure (AFBS) usage as sensors in MPSS. The mathematical model of additive response from a single MAFBS is presented. The MAFBS is a special type of Fiber Bragg Gratings (FBG), the reflection spectrum of which has three (or more) narrow notches. The frequencies of narrow notches are located in the infrared range of electromagnetic spectrum, while differences between them are located in the microwave frequency range. All cross-differences between optical frequencies of single MAFBS are called the address frequencies set. When the additive optical response from a single MAFBS, passed through an optic filter with an oblique amplitude–frequency characteristic, is received on a photodetector, the complex electrical signal, which consists of all cross-frequency beatings of all optical frequencies, which are included in this optical signal, is taken at its output. This complex electrical signal at the photodetector’s output contains enough information to determine the central frequency shift of the MAFBS. The method of address frequencies analysis with the microwave-photonic measuring conversion method, which allows us to define the central frequency shift of a single MAFBS, is discussed in the work.

scholarly journals Multicast Fiber Bragg Structures in Microwave Photonics Sensor Systems

2020 ◽  
Vol 6 (1) ◽  
pp. 6-13
Author(s):  
T. Agliullin ◽  
V. Anfinogentov ◽  
R. Misbahov ◽  
O. Morozov ◽  
A. Sakhabutdinov
Keyword(s):  
Narrow Band ◽  
Microwave Frequency ◽  
Microwave Photonics ◽  
Sensor Systems ◽  
Bragg Structure ◽  
Band Frequency ◽  
Bragg Structures ◽  
Frequency Components ◽  
Physical Fields ◽  
The Difference

The article describes the transition concept from addressable fiber Bragg structures and microwave-photonics sensor systems based on them to multicast fiber Bragg structures. The difference between multicast structures and address structures is that in the fiber Bragg structure formes three or more super narrow-band frequency components, spaced from each other by the microwave frequency. The central frequencies shift of multicast Bragg structures is determined by the result of processing the signal of optical frequencies beats at the photodetector, which parameters judge the applied physical fields. We see the solved problem of uniquely determining the central (Bragg) frequency shift of the multicast fiber Bragg structure, with a unique set of address frequencies.

scholarly journals A High Sensitivity Self-Powered Wind Speed Sensor Based on Triboelectric Nanogenerators (TENGs)

Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 2951
Author(s):  
Yangming Liu ◽  
Jialin Liu ◽  
Lufeng Che
Keyword(s):  
Wind Speed ◽  
High Sensitivity ◽  
Electrical Signal ◽  
Geometrical Parameters ◽  
Sensor Systems ◽  
Speed Sensor ◽  
Speed Range ◽  
Self Powered ◽  
Triboelectric Nanogenerators ◽  
Application Prospects

Triboelectric nanogenerators (TENGs) have excellent properties in harvesting tiny environmental energy and self-powered sensor systems with extensive application prospects. Here, we report a high sensitivity self-powered wind speed sensor based on triboelectric nanogenerators (TENGs). The sensor consists of the upper and lower two identical TENGs. The output electrical signal of each TENG can be used to detect wind speed so that we can make sure that the measurement is correct by two TENGs. We study the influence of different geometrical parameters on its sensitivity and then select a set of parameters with a relatively good output electrical signal. The sensitivity of the wind speed sensor with this set of parameters is 1.79 μA/(m/s) under a wind speed range from 15 m/s to 25 m/s. The sensor can light 50 LEDs at the wind speed of 15 m/s. This work not only advances the development of self-powered wind sensor systems but also promotes the application of wind speed sensing.

scholarly journals Guided Optical Modes in Metal-Cladded Tunable Hyperbolic Metamaterial Slab Waveguides

Crystals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 176 ◽  
Author(s):  
Marcin Kieliszczyk ◽  
Bartosz Janaszek ◽  
Anna Tyszka-Zawadzka ◽  
Paweł Szczepański
Keyword(s):  
Power Flow ◽  
Guided Waves ◽  
Flow Direction ◽  
Nonlinear Effects ◽  
Optical Signal ◽  
Infrared Range ◽  
Graphene Sheets ◽  
Hyperbolic Metamaterial ◽  
Practical Applications ◽  
Optical Modes

We have theoretically investigated metal-cladded waveguides of tunable hyperbolic metamaterial (THMM) cores, employing graphene sheets as a tunable layer, in terms of guided waves propagation over near- to mid-infrared range, following the effective medium approximation. We have proven that these subwavelength guiding structures offer a number of effects usually not found in other types of waveguides, including controllable propagation gap and number of modes, inversion of power flow direction with respect to phase velocity, TM mode propagation, and absence of the fundamental mode, which occur as a result of controlled change of the guiding layer dispersion regime. This is the first time that the above-mentioned effects are obtained with a single, voltage-controlled waveguiding structure comprising graphene sheets and a dielectric, although the presented methodology allows us to incorporate other tunable materials beyond graphene equally well. We believe that such or similar structures, feasible by means of current planar deposition techniques, will ultimately find their practical applications in optical signal processing, controlled phase matching, controlled coupling, signal modulation, or the enhancement of nonlinear effects.

Photonic Generation of Microwave Frequency Shift Keying Signals

2016 ◽  
Vol 28 (18) ◽  
pp. 1928-1931 ◽  
Author(s):  
Long Huang ◽  
Peng Wang ◽  
Peng Xiang ◽  
Dalei Chen ◽  
Yiyun Zhang ◽  
...  
Keyword(s):  
Frequency Shift ◽  
Microwave Frequency ◽  
Frequency Shift Keying ◽  
Photonic Generation ◽  
Shift Keying

Fiber Bragg Grating Demodulation System Based on Equi-Intensity Cantilever Beam

2010 ◽  
Vol 437 ◽  
pp. 359-363
Author(s):  
Hong Li ◽  
Wei Ping Yan ◽  
Ren Sheng Shen ◽  
Ben Yu Wang
Keyword(s):  
Fiber Bragg Grating ◽  
Cantilever Beam ◽  
Optical Spectrum ◽  
Optical Signal ◽  
Electrical Signal ◽  
Bragg Grating ◽  
Wavelength Shift ◽  
Optical Spectrum Analyzer ◽  
Bragg Wavelength ◽  
Scanning Velocity

Optical spectrum analyzer (OSA) can achieve the higher precision and sensitivity, but it is disadvantageous for translating optical signal into electrical signal. A fiber Bragg grating (FBG) matched filtering system based on equi-intensity cantilever beam was presented in this paper. Strain characteristics in different location of cantilever beam were described, and the strain sensitivity of matching grating demodulation based on equi-intensity cantilever beam was deduced mathematically. Strain characteristics of cantilever beam were verified, and the sensing effect of the system was tested. The Bragg wavelength shift range of the demodulating FBG placed on the cantilever beam reached 10 nm, and scanning velocity was 0.125 nm/s. The system could demodulate slow-altered sensing signal accurately and rapidly.

scholarly journals Switchable and tunable microwave frequency multiplication based on a dual-passband microwave photonic filter

2015 ◽  
Vol 23 (8) ◽  
pp. 9835 ◽  
Author(s):  
Hao Chen ◽  
Zuowei Xu ◽  
Hongyan Fu ◽  
Shiwei Zhang ◽  
Congxian Wu ◽  
...  
Keyword(s):  
Microwave Frequency ◽  
Frequency Multiplication ◽  
Microwave Photonic ◽  
Tunable Microwave

scholarly journals Modulation Characteristics of Period-One Oscillations in Quantum Cascade Lasers

2021 ◽  
Vol 11 (24) ◽  
pp. 11730
Author(s):  
Binbin Zhao ◽  
Yibo Peng ◽  
Xingguang Wang ◽  
Cheng Wang
Keyword(s):  
Quantum Cascade Lasers ◽  
Optical Feedback ◽  
Coupling Effect ◽  
Modulation Depth ◽  
Low Frequency ◽  
Optical Signal ◽  
Electrical Signal ◽  
Periodic Oscillations ◽  
Quantum Cascade ◽  
Cascade Lasers

Quantum cascade lasers subject to tilted optical feedback produce periodic oscillations, quasi-periodic oscillations, and low-frequency oscillations. This work presents the modulation characteristics of period-one (P1) oscillations in a quantum cascade laser with tilted optical feedback. The electrical signal at the oscillation frequency is more than 50 dB higher than the noise level, and the electrical linewidth is less than 2.0 kHz. This electrical linewidth is about four orders of magnitude narrower than the optical linewidth (around 16 MHz) of the free-running laser, which suggests that the optical sidebands induced by the P1 oscillations are highly coherent with the main optical mode. In addition, the modulation depth of the optical signal is found to be in the range of 1% to 3.5%. In addition, it is verified in the simulations that the P1 oscillations induce not only amplitude modulation but also frequency modulation due to the phase-amplitude coupling effect.

scholarly journals The Application of Low-Frequency Transition in the Assessment of the Second-Order Zeeman Frequency Shift

Sensors ◽  
2021 ◽  
Vol 21 (24) ◽  
pp. 8333
Author(s):  
Yang Bai ◽  
Xinliang Wang ◽  
Junru Shi ◽  
Fan Yang ◽  
Jun Ruan ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Frequency Shift ◽  
Low Frequency ◽  
Pulse Signal ◽  
Second Order ◽  
Magnetic Field Measurement ◽  
Central Frequency ◽  
Zeeman Frequency ◽  
The Magnetic Field ◽  
Frequency Pulse

Second-order Zeeman frequency shift is one of the major systematic factors affecting the frequency uncertainty performance of cesium atomic fountain clock. Second-order Zeeman frequency shift is calculated by experimentally measuring the central frequency of the (1,1) or (−1,−1) magnetically sensitive Ramsey transition. The low-frequency transition method can be used to measure the magnetic field strength and to predict the central fringe of (1,1) or (−1,−1) magnetically sensitive Ramsey transition. In this paper, we deduce the formula for magnetic field measurement using the low-frequency transition method and measured the magnetic field distribution of 4 cm inside the Ramsey cavity and 32 cm along the flight region experimentally. The result shows that the magnetic field fluctuation is less than 1 nT. The influence of low-frequency pulse signal duration on the accuracy of magnetic field measurement is studied and the optimal low-frequency pulse signal duration is determined. The central fringe of (−1,−1) magnetically sensitive Ramsey transition can be predicted by using a numerical integrating of the magnetic field “map”. Comparing the predicted central fringe with that identified by Ramsey method, the frequency difference between these two is, at most, a fringe width of 0.3. We apply the experimentally measured central frequency of the (−1,−1) Ramsey transition to the Breit-Rabi formula, and the second-order Zeeman frequency shift is calculated as 131.03 × 10−15, with the uncertainty of 0.10 × 10−15.

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