Results 101 to 110 of about 25,049 (217)

Φ-OTDR Based on Undersampling Heterodyne Detection

Applied Sciences
We demonstrate a distributed acoustic sensing (DAS) system based on phase-sensitive optical time-domain reflectometry (Φ-OTDR) that employs I/Q demodulation and heterodyne detection.
Jiaxiang Feng, Dandan Zhang, Yuan Mao
doaj   +1 more source

Thermal background noise limitations [PDF]

Modern detection systems are increasingly limited in sensitivity by the background thermal photons which enter the receiving system. Expressions for the fluctuations of detected thermal radiation are derived. Incoherent and heterodyne detection processes
Gulkis, S.
core   +1 more source

Instantaneous quadrature low-coherence interferometry with 3x3 fiber-optic couplers [PDF]

, 2003
We describe fiber-based quadrature low-coherence interferometers that exploit the inherent phase shifts of 3 x 3 and higher-order fiber-optic couplers. We present a framework based on conservation of energy to account for the interferometric shifts in 3 ...
Choma, Michael A., Izatt, Joseph A., Yang, Changhuei   +2 more
core  

Remote sensing of atmospheric winds using a coherent, CW lidar and speckle-turbulence interaction [PDF]

, 1986
Speckle turbulence interaction has the potential for allowing single ended remote sensing of the path averaged vector crosswind in a plane perpendicular to the line of sight to a target.
Amzajerdian, F., Gudimetla, V. S. R., Holmes, J. F., Hunt, J. M.   +3 more
core   +1 more source

Comment on "Self-Referenced Coherent Diffraction X-Ray Movie of \AA ngstrom- and Femtosecond-Scale Atomic Motion"

, 2017
This submission is a comment on an article that had previously appeared in Phys. Rev. Lett.Comment: Phys. Rev. Lett.
Bennett, Kochise, Kowalewski, Markus, Mukamel, Shaul   +2 more
core   +1 more source

Compensation for the Decoherence Effect in Heterodyne Detection of Rough Targets and a Target Vibration Characteristic Measurement System. [PDF]

Sci Rep, 2020
Cao C, Su X, Liu Y, Zeng X, Feng Z, Shen J, Wang T, Yan X.   +7 more
europepmc   +1 more source

3D Fourier imaging based on 2D heterodyne detection at THz frequencies

APL Photonics, 2019
Holographic imaging techniques, which exploit the coherence properties of light, enable the reconstruction of the 3D scenery being viewed. While the standard approaches for the recording of holographic images require the superposition of scattered light ...
Hui Yuan, Daniel Voß, Alvydas Lisauskas, David Mundy, Hartmut G. Roskos   +4 more
doaj   +1 more source

Extended imaging depth of en-face optical coherence tomography based on fast measurement of a reflection matrix by wide-field heterodyne detection. [PDF]

Opt Lett, 2020
Yang Q, Cao J, Miao Y, Zhu J, Chen Z.
europepmc   +1 more source

Broadband heterodyne electro-optic sampling using a lithium niobate ridge-waveguide

Applied Physics Express
We demonstrated the bandwidth broadening of terahertz waves detected by heterodyne electro-optical sampling by implementing a ridge waveguide structure in a lithium niobate (LiNbO _3 ) crystal.
S. Mine, G. Gandubert, J. E. Nkeck, X. Ropagnol, K. Murate, F. Blanchard   +5 more
doaj   +1 more source

A New Acoustic Emission Sensor Based Gear Fault Detection Approach [PDF]

International Journal of Prognostics and Health Management, 2013
In order to reduce wind energy costs, prognostics and health management (PHM) of wind turbine is needed to ensure the reliability and availability of wind turbines. A gearbox is an important component of a wind turbine.
Junda Zhu, Eric Bechhoefer, David He, Yongzhi Qu   +3 more
doaj