Coherent detection of stimulated Brillouin backscatter on photoconductive three-wave mixer for sensing applications

1989 ◽  
Vol 25 (18) ◽  
pp. 1236 ◽  
Author(s):  
J.K.A. Everard ◽  
R. Thomas
Keyword(s):  
Coherent Detection ◽  
Sensing Applications ◽  
Stimulated Brillouin

scholarly journals Terahertz quantum sensing

2020 ◽  
Vol 6 (11) ◽  
pp. eaaz8065 ◽  
Author(s):  
Mirco Kutas ◽  
Björn Haase ◽  
Patricia Bickert ◽  
Felix Riexinger ◽  
Daniel Molter ◽  
...  
Keyword(s):  
Layer Thickness ◽  
Region Of Interest ◽  
Coherent Detection ◽  
Semiconductor Detectors ◽  
Terahertz Frequency ◽  
Sensing Applications ◽  
Highly Sensitive ◽  
Quantum Sensing ◽  
Thickness Measurements ◽  
Detection Schemes

Quantum sensing is highly attractive for accessing spectral regions in which the detection of photons is technically challenging: Sample information is gained in the spectral region of interest and transferred via biphoton correlations into another spectral range, for which highly sensitive detectors are available. This is especially beneficial for terahertz radiation, where no semiconductor detectors are available and coherent detection schemes or cryogenically cooled bolometers have to be used. Here, we report on the first demonstration of quantum sensing in the terahertz frequency range in which the terahertz photons interact with a sample in free space and information about the sample thickness is obtained by the detection of visible photons. As a first demonstration, we show layer thickness measurements with terahertz photons based on biphoton interference. As nondestructive layer thickness measurements are of high industrial relevance, our experiments might be seen as a first step toward industrial quantum sensing applications.

scholarly journals Low Computational Cost Distributed Acoustic Sensing Using Analog I/Q Demodulation

Sensors ◽  
2019 ◽  
Vol 19 (17) ◽  
pp. 3753 ◽  
Author(s):  
Fei Jiang ◽  
Zixiao Lu ◽  
Feida Cai ◽  
Honglang Li ◽  
Zhenhai Zhang ◽  
...  
Keyword(s):  
Beat Frequency ◽  
Computational Cost ◽  
Digital Processing ◽  
Time Domain Reflectometry ◽  
Coherent Detection ◽  
Universal Method ◽  
Acoustic Sensing ◽  
Sensing Applications ◽  
Distributed Acoustic Sensing ◽  
Phase Demodulation

Distributed acoustic sensing based on phase-sensitive optical time-domain reflectometry (Φ-OTDR) has been widely used in many fields. Phase demodulation of the Φ-OTDR signal is essential for undistorted acoustic measurement. Digital coherent detection is a universal method to implement phase demodulation, but it may cause severe computational burden. In this paper, analog I/Q demodulation is introduced into the Φ-OTDR based DAS system to solve this problem, which can directly obtain the I and Q components of the beat signal without any digital processing, meaning that the computational cost can be sharply reduced. Besides, the sampling frequency of the data acquisition card can theoretically be lower than the beat frequency as the spectrum aliasing would not affect the demodulation results, thus further reducing the data volume of the system. Experimental results show that the proposed DAS system can demodulate the phase signal with good linearity and wide frequency response range. It can also adequately recover the sound signal sensed by the optical fiber, indicating that it can be a promising solution for computational-cost-sensitive distributed acoustic sensing applications.

Stimulated Brillouin laser-based carrier recovery in a high-Q microcavity for coherent detection

2020 ◽  
Vol 45 (14) ◽  
pp. 3848
Author(s):  
Qin Wen ◽  
Jinhui Qin ◽  
Yong Geng ◽  
Guangwei Deng ◽  
Qiang Zhou ◽  
...  
Keyword(s):  
Coherent Detection ◽  
Carrier Recovery ◽  
High Q ◽  
Stimulated Brillouin

scholarly journals System feasibility of using stimulated Brillouin scattering in self coherent detection schemes

2010 ◽  
Vol 18 (12) ◽  
pp. 12702 ◽  
Author(s):  
Luca Banchi ◽  
Marco Presi ◽  
Roberto Proietti ◽  
Ernesto Ciaramella
Keyword(s):  
Brillouin Scattering ◽  
Stimulated Brillouin Scattering ◽  
Coherent Detection ◽  
Stimulated Brillouin ◽  
Detection Schemes

Computer simulation study about the dependence of amorphous silicon photonic waveguides efficiency on the material quality

2020 ◽  
Vol 90 (3) ◽  
pp. 30502
Author(s):  
Alessandro Fantoni ◽  
João Costa ◽  
Paulo Lourenço ◽  
Manuela Vieira
Keyword(s):  
Amorphous Silicon ◽  
High Throughput Screening ◽  
Simulation Analysis ◽  
Low Cost ◽  
Deposition Process ◽  
Large Area ◽  
Sidewall Roughness ◽  
Sensing Applications ◽  
Fabrication Defects ◽  
The Impact

Amorphous silicon PECVD photonic integrated devices are promising candidates for low cost sensing applications. This manuscript reports a simulation analysis about the impact on the overall efficiency caused by the lithography imperfections in the deposition process. The tolerance to the fabrication defects of a photonic sensor based on surface plasmonic resonance is analysed. The simulations are performed with FDTD and BPM algorithms. The device is a plasmonic interferometer composed by an a-Si:H waveguide covered by a thin gold layer. The sensing analysis is performed by equally splitting the input light into two arms, allowing the sensor to be calibrated by its reference arm. Two different 1 × 2 power splitter configurations are presented: a directional coupler and a multimode interference splitter. The waveguide sidewall roughness is considered as the major negative effect caused by deposition imperfections. The simulation results show that plasmonic effects can be excited in the interferometric waveguide structure, allowing a sensing device with enough sensitivity to support the functioning of a bio sensor for high throughput screening. In addition, the good tolerance to the waveguide wall roughness, points out the PECVD deposition technique as reliable method for the overall sensor system to be produced in a low-cost system. The large area deposition of photonics structures, allowed by the PECVD method, can be explored to design a multiplexed system for analysis of multiple biomarkers to further increase the tolerance to fabrication defects.

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