In electrical engineering, homodyne detection is a method of extracting information encoded as modulation of the phase and/or frequency of an oscillating signal, by comparing that signal with a standard oscillation that would be identical to the signal if it carried null information. "Homodyne" signifies a single frequency, in contrast to the dual frequencies employed in heterodyne detection.
Optical homodyne detection
When applied to processing of the reflected signal in remote sensing for topography, homodyne detection lacks the ability of heterodyne detection to determine the size of a static discontinuity in elevation between two locations. (If there is a path between the two locations with smoothly changing elevation, then homodyne detection may in principle be able to track the signal phase along the path if sampling is dense enough). Homodyne detection is more readily applicable to velocity sensing.
In optical interferometry, homodyne signifies that the reference radiation (i.e. the local oscillator) is derived from the same source as the signal before the modulating process. For example, in a laser scattering measurement, the laser beam is split into two parts. One is the local oscillator and the other is sent to the system to be probed. The scattered light is then mixed with the local oscillator on the detector. This arrangement has the advantage of being insensitive to fluctuations in the frequency of the laser. Usually the scattered beam will be weak, in which case the (nearly) steady component of the detector output is a good measure of the instantaneous local oscillator intensity and therefore can be used to compensate for any fluctuations in the intensity of the laser.[1][2][clarification needed]
Radio technologyedit
In radio technology, the distinction is not the source of the local oscillator, but the frequency used. In heterodyne detection, the local oscillator is frequency-shifted, while in homodyne detection it has the same frequency as the radiation to be detected. See direct conversion receiver.
Applicationsedit
Lock-in amplifiers are homodyne detectors integrated into measurement equipment or packaged as stand-alone laboratory equipment for sensitive detection and highly selective filtering of weak or noisy signals. Homodyne/lock-in detection has been one of the most commonly used signal processing methods across a wide range of experimental disciplines for decades.
Homodyne and heterodyne techniques are commonly used in thermoreflectance techniques.
In the processing of signals in some applications of magnetic resonance imaging, homodyne detection can offer advantages over magnitude detection. The homodyne technique can suppress excessive noise and undesired quadrature components (90° out-of-phase), and provide stable access to information that may be encoded into the phase or polarity of images.[3]
^Chapman, Mark (2002). . Renishaw plc (UK). Archived from the original on 26 July 2017. Retrieved 14 February 2017.
^ abXu, Qing (2009). Optical Homodyne Detections and Applications in Quantum Cryptography(PDF) (Thesis). Paris: Télécom ParisTech. Retrieved 14 February 2017.
^Noll, D. C.; Nishimura, D. G.; Macovski, A. (1991). "Homodyne detection in magnetic resonance imaging". IEEE Transactions on Medical Imaging. 10 (2): 154–163. doi:10.1109/42.79473. ISSN 0278-0062.
^Maria Fuwa; Shuntaro Takeda; Marcin Zwierz; Howard M. Wiseman; Akira Furusawa (24 March 2015). "Experimental proof of nonlocal wavefunction collapse for a single particle using homodyne measurements". Nature Communications. 6 (6665): 6665. arXiv:1412.7790. Bibcode:2015NatCo...6E6665F. doi:10.1038/ncomms7665. PMID 25801071.
External linksedit
Su, Shi-Lei; Wang, Yuan; Guo, Qi; Wang, Hong-Fu; Zhang, Shou (2012). "Generating a four-photon polarization-entangled cluster state with homodyne measurement via cross-Kerr nonlinearity". Chinese Physics B. 21 (4): 044205. Bibcode:2012ChPhB..21d4205S. doi:10.1088/1674-1056/21/4/044205. ISSN 1674-1056.
April 11, 2024
homodyne, detection, this, article, needs, additional, citations, verification, please, help, improve, this, article, adding, citations, reliable, sources, unsourced, material, challenged, removed, find, sources, news, newspapers, books, scholar, jstor, march,. This article needs additional citations for verification Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources Homodyne detection news newspapers books scholar JSTOR March 2015 Learn how and when to remove this template message In electrical engineering homodyne detection is a method of extracting information encoded as modulation of the phase and or frequency of an oscillating signal by comparing that signal with a standard oscillation that would be identical to the signal if it carried null information Homodyne signifies a single frequency in contrast to the dual frequencies employed in heterodyne detection Optical homodyne detectionWhen applied to processing of the reflected signal in remote sensing for topography homodyne detection lacks the ability of heterodyne detection to determine the size of a static discontinuity in elevation between two locations If there is a path between the two locations with smoothly changing elevation then homodyne detection may in principle be able to track the signal phase along the path if sampling is dense enough Homodyne detection is more readily applicable to velocity sensing Contents 1 In optics 2 Radio technology 3 Applications 4 See also 5 References 6 External linksIn optics editIn optical interferometry homodyne signifies that the reference radiation i e the local oscillator is derived from the same source as the signal before the modulating process For example in a laser scattering measurement the laser beam is split into two parts One is the local oscillator and the other is sent to the system to be probed The scattered light is then mixed with the local oscillator on the detector This arrangement has the advantage of being insensitive to fluctuations in the frequency of the laser Usually the scattered beam will be weak in which case the nearly steady component of the detector output is a good measure of the instantaneous local oscillator intensity and therefore can be used to compensate for any fluctuations in the intensity of the laser 1 2 clarification needed Radio technology editIn radio technology the distinction is not the source of the local oscillator but the frequency used In heterodyne detection the local oscillator is frequency shifted while in homodyne detection it has the same frequency as the radiation to be detected See direct conversion receiver Applications editLock in amplifiers are homodyne detectors integrated into measurement equipment or packaged as stand alone laboratory equipment for sensitive detection and highly selective filtering of weak or noisy signals Homodyne lock in detection has been one of the most commonly used signal processing methods across a wide range of experimental disciplines for decades Homodyne and heterodyne techniques are commonly used in thermoreflectance techniques In the processing of signals in some applications of magnetic resonance imaging homodyne detection can offer advantages over magnitude detection The homodyne technique can suppress excessive noise and undesired quadrature components 90 out of phase and provide stable access to information that may be encoded into the phase or polarity of images 3 An encrypted secure communication system can be based on quantum key distribution QKD An efficient receiver scheme for implementing QKD is balanced homodyne detection BHD using a positive intrinsic negative PIN diode 2 Homodyne detection was one of the key techniques in demonstrating quantum entanglement 4 See also editHeterodyne Heterodyne detection Optical heterodyne detectionReferences edit Chapman Mark 2002 Heterodyne and homodyne interferometry Renishaw plc UK Archived from the original on 26 July 2017 Retrieved 14 February 2017 a b Xu Qing 2009 Optical Homodyne Detections and Applications in Quantum Cryptography PDF Thesis Paris Telecom ParisTech Retrieved 14 February 2017 Noll D C Nishimura D G Macovski A 1991 Homodyne detection in magnetic resonance imaging IEEE Transactions on Medical Imaging 10 2 154 163 doi 10 1109 42 79473 ISSN 0278 0062 Maria Fuwa Shuntaro Takeda Marcin Zwierz Howard M Wiseman Akira Furusawa 24 March 2015 Experimental proof of nonlocal wavefunction collapse for a single particle using homodyne measurements Nature Communications 6 6665 6665 arXiv 1412 7790 Bibcode 2015NatCo 6E6665F doi 10 1038 ncomms7665 PMID 25801071 External links editSu Shi Lei Wang Yuan Guo Qi Wang Hong Fu Zhang Shou 2012 Generating a four photon polarization entangled cluster state with homodyne measurement via cross Kerr nonlinearity Chinese Physics B 21 4 044205 Bibcode 2012ChPhB 21d4205S doi 10 1088 1674 1056 21 4 044205 ISSN 1674 1056 Retrieved from https en wikipedia org w index php title Homodyne detection amp oldid 1188600389, wikipedia, wiki, book, books, library,
