In this work, the spacetime distributions of the electric and magnetic fields of photon are revealed. It is first time found that the spacetime distributions of electric and magnetic fields of photon are source dependent. Based on this discovery, some potential applications are discussed.
{"title":"What the Photon Looks Like?","authors":"Wei-Xing Xu","doi":"10.4236/opj.2020.104004","DOIUrl":"https://doi.org/10.4236/opj.2020.104004","url":null,"abstract":"In this work, the spacetime distributions of the electric and magnetic fields of photon are revealed. It is first time found that the spacetime distributions of electric and magnetic fields of photon are source dependent. Based on this discovery, some potential applications are discussed.","PeriodicalId":64491,"journal":{"name":"光学与光子学期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48416020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Raoule J. O. Agoua, A. Kamagate, A. Konaté, M. Menif, O. Asseu
Larger wireless access networks are required to meet the growing demand for mobile traffic and multimedia services. The use of RoF (Radio over Fiber) technology in combination with millimeter waves is a potential response to the requirements of broadband applications and high capacity networks. In this paper, we proposed a RoF architecture able to provide very high-speed wireless access points up to Gbps considering an indoor and outdoor environment conform to IEEE 802.11ad and IEEE 802.15.3c standard. Optical transmission and radio coverage have been studied by considering the uplink and downlink. System performance has been evaluated in the relation to the Error Vector Magnitude (EVM) for various modulation formats (BPSK, QPSK and 16QAM). Results showed that millimeter wave signals are successfully delivered over a 50 km fiber link and a wireless channel up to 32 m. Data throughput up to 5.28 Gbps has been reached. The proposed architecture can extend the range of applications for wireless communications in association with the unlicensed 60 GHz band with the advantages of better capacity, a wider coverage area and a reduction in the investment cost.
{"title":"Radio over Fiber Architecture Very High-Speed Wireless Communications in the Unlicensed 60 GHz Band","authors":"Raoule J. O. Agoua, A. Kamagate, A. Konaté, M. Menif, O. Asseu","doi":"10.4236/opj.2020.103003","DOIUrl":"https://doi.org/10.4236/opj.2020.103003","url":null,"abstract":"Larger wireless access networks are required to meet the growing demand for mobile traffic and multimedia services. The use of RoF (Radio over Fiber) technology in combination with millimeter waves is a potential response to the requirements of broadband applications and high capacity networks. In this paper, we proposed a RoF architecture able to provide very high-speed wireless access points up to Gbps considering an indoor and outdoor environment conform to IEEE 802.11ad and IEEE 802.15.3c standard. Optical transmission and radio coverage have been studied by considering the uplink and downlink. System performance has been evaluated in the relation to the Error Vector Magnitude (EVM) for various modulation formats (BPSK, QPSK and 16QAM). Results showed that millimeter wave signals are successfully delivered over a 50 km fiber link and a wireless channel up to 32 m. Data throughput up to 5.28 Gbps has been reached. The proposed architecture can extend the range of applications for wireless communications in association with the unlicensed 60 GHz band with the advantages of better capacity, a wider coverage area and a reduction in the investment cost.","PeriodicalId":64491,"journal":{"name":"光学与光子学期刊(英文)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43137234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Spiral polarization rotators, rotating polarization ellipse axes clockwise or counterclockwise, depending on the azimuth angle in the transverse plane, are considered. It is shown that spiral polarization rotators lead to a change in the order of optical vortices with circular polarization. A comparative analysis of spiral rotators of two types (polar and non-polar) is carried out, using a mirror that allows light to pass in the opposite direction through the rotator. The effect of spiral rotators on optical vortices in a resonator is studied. It is shown that spiral rotators can preserve or accumulate changes of the vortex order during the passage of the beam in both directions. The properties of the spiral rotator and the cube-corner reflector with a special phase-correcting coating, as a diffractive polarization-optical element, are compared.
{"title":"Comparative Analysis of the Characteristics of Polar and Non-Polar Spiral Polarization Rotators","authors":"A. Sokolov","doi":"10.4236/opj.2020.102002","DOIUrl":"https://doi.org/10.4236/opj.2020.102002","url":null,"abstract":"Spiral polarization rotators, rotating polarization ellipse axes clockwise or counterclockwise, depending on the azimuth angle in the transverse plane, are considered. It is shown that spiral polarization rotators lead to a change in the order of optical vortices with circular polarization. A comparative analysis of spiral rotators of two types (polar and non-polar) is carried out, using a mirror that allows light to pass in the opposite direction through the rotator. The effect of spiral rotators on optical vortices in a resonator is studied. It is shown that spiral rotators can preserve or accumulate changes of the vortex order during the passage of the beam in both directions. The properties of the spiral rotator and the cube-corner reflector with a special phase-correcting coating, as a diffractive polarization-optical element, are compared.","PeriodicalId":64491,"journal":{"name":"光学与光子学期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46777761","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The variation of the temperature of the solar cell subjected to the incident global solar radiation along the local daytime in relation to its efficiency is studied. The heat balance equation is solved. The solution revealed that the cell temperature is a function of the maximum value of the daily incident global solar radiation qmax, the convection heat transfer coefficient (h), the optical, physical and the geometrical parameters of the cell. The temperature dependence of the short circuit current Isc, the dark saturation current Io, the open circuit voltage Voc, and the energy band gap Eg characterizing a Silicon solar cell is considered in evaluating the cell efficiency. Computations of the efficiency concerning operating conditions and astronomical locations (Egypt) as illustrative examples are given.
{"title":"The Solar Cell Parameters as a Function of Its Temperature in Relation to Its Diurnal Efficiency","authors":"Samia Sayed Shaban","doi":"10.4236/opj.2020.101001","DOIUrl":"https://doi.org/10.4236/opj.2020.101001","url":null,"abstract":"The variation of the temperature of the solar cell subjected to the incident global solar radiation along the local daytime in relation to its efficiency is studied. The heat balance equation is solved. The solution revealed that the cell temperature is a function of the maximum value of the daily incident global solar radiation qmax, the convection heat transfer coefficient (h), the optical, physical and the geometrical parameters of the cell. The temperature dependence of the short circuit current Isc, the dark saturation current Io, the open circuit voltage Voc, and the energy band gap Eg characterizing a Silicon solar cell is considered in evaluating the cell efficiency. Computations of the efficiency concerning operating conditions and astronomical locations (Egypt) as illustrative examples are given.","PeriodicalId":64491,"journal":{"name":"光学与光子学期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49173882","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In recent years, multi-target tracking technology based on Gaussian Mixture- Probability Hypothesis Density (GM-PHD) filtering has become a hot field of information fusion research. This article outlines the generation and development of multi-target tracking methods based on GM-PHD filtering, and the principle and implementation method of GM-PHD filtering are explained, and the application status based on GM-PHD filtering is summarized, and the key issues of the development of GM-PHD filtering technology are analyzed.
{"title":"Research and Application of Multi-Target Tracking Based on GM-PHD Filter","authors":"Yanyi Li, Limin Guo, Xiangsong Huang","doi":"10.4236/opj.2020.106013","DOIUrl":"https://doi.org/10.4236/opj.2020.106013","url":null,"abstract":"In recent years, multi-target tracking technology based on Gaussian Mixture- Probability Hypothesis Density (GM-PHD) filtering has become a hot field of information fusion research. This article outlines the generation and development of multi-target tracking methods based on GM-PHD filtering, and the principle and implementation method of GM-PHD filtering are explained, and the application status based on GM-PHD filtering is summarized, and the key issues of the development of GM-PHD filtering technology are analyzed.","PeriodicalId":64491,"journal":{"name":"光学与光子学期刊(英文)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70714393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We present a mode converter and demultiplexer structure for wavelength division multiplexing (WDM) transmission by employing multimode interference (MMI) on Silicon-on-Insulator (SOI) platform. The mode converter and demultiplexer have a compact size of less than 2.7 μm × 43.7 μm. Moreover, the crosstalk between neighboring wavelength channel within C band (1530 nm to 1570 nm) can be reduced by utilizing the tapered phase shifter cascaded with MMI. The simulated results indicate that this structure has a low insertion loss of less than 1 dB, a low crosstalk of better than ?15 dB and a relatively high fabrication tolerance of ~10 nm. Such structure may find many potential applications in silicon photonic integrated devices.
{"title":"Silicon-Based Mode Converter and Demultiplexer for Wavelength Division Multiplexing Transmission by Using Multimode Interference Couplers","authors":"Yong Zhou, Junqiang Sun","doi":"10.4236/opj.2020.106012","DOIUrl":"https://doi.org/10.4236/opj.2020.106012","url":null,"abstract":"We present a mode converter and demultiplexer structure for wavelength division multiplexing (WDM) transmission by employing multimode interference (MMI) on Silicon-on-Insulator (SOI) platform. The mode converter and demultiplexer have a compact size of less than 2.7 μm × 43.7 μm. Moreover, the crosstalk between neighboring wavelength channel within C band (1530 nm to 1570 nm) can be reduced by utilizing the tapered phase shifter cascaded with MMI. The simulated results indicate that this structure has a low insertion loss of less than 1 dB, a low crosstalk of better than ?15 dB and a relatively high fabrication tolerance of ~10 nm. Such structure may find many potential applications in silicon photonic integrated devices.","PeriodicalId":64491,"journal":{"name":"光学与光子学期刊(英文)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70714353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The analytical expression of the cross-spectral density of partially coherent elegant Laguerre-Gaussian beams propagating in free space has been derived. The coherence vortex properties of such beams have been investigated. The effect of the beam parameters, including the topological charge, radial mode index and coherence length on the coherent vortex, is analyzed. The results show that the higher order (lth) of coherent vortices split to lth first order of coherent vortex. New coherent vortices of opposite sign appear, and then pairs of coherent vortices form. The propagation distance and coherence length affect the generation of coherent vortices, while the radial mode index doesn’t affect the coherent vortices. These results might be helpful for potential application of such beams in optical communication.
{"title":"Coherent Vortices Properties of Partially Coherent Elegant Laguerre-Gaussian Beams in the Free Space","authors":"M. Dong, Yuanjie Yang","doi":"10.4236/opj.2020.106017","DOIUrl":"https://doi.org/10.4236/opj.2020.106017","url":null,"abstract":"The analytical expression of the cross-spectral density of partially coherent elegant Laguerre-Gaussian beams propagating in free space has been derived. The coherence vortex properties of such beams have been investigated. The effect of the beam parameters, including the topological charge, radial mode index and coherence length on the coherent vortex, is analyzed. The results show that the higher order (lth) of coherent vortices split to lth first order of coherent vortex. New coherent vortices of opposite sign appear, and then pairs of coherent vortices form. The propagation distance and coherence length affect the generation of coherent vortices, while the radial mode index doesn’t affect the coherent vortices. These results might be helpful for potential application of such beams in optical communication.","PeriodicalId":64491,"journal":{"name":"光学与光子学期刊(英文)","volume":"10 1","pages":"159-166"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70714442","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.4236/opj.2020.1010023
I. Kompanets, N. Zalyapin
Speckles in images formed by a laser beam are interference noise arising due to coherent nature of laser radiation. As the number of projection systems using laser light sources increases, new methods and devices appear for reducing the contrast of speckle-noise and thereby suppressing it. Taking into account the long-standing nature of the problem and the continuing relev-ance of its solution, this review discusses modern practical methods and de-vices—despecklers, used to reduce the speckle contrast and to achieve high quality of projected images. The review discusses the nature of the speckles appearance, considers their statistical properties, and describes the measurement of the speckle contrast. The requirements for despecklers are considered, the most important of which are speckle suppression efficiency, sim-plicity of design and compactness, low power consumption and low optical loss. The characteristics of different types of despecklers, including diffusers, devices based on electroactive polymers, optical waveguides, colloidal solutions and liquid crystals, as well as orthogonal phase matrices and diffraction gratings proposed as despeckers, are examined in detail. It is shown that despecklers with decorrelation of the phase front based on the mirror deformation and optical fiber have less light losses. Electro-optical-liquid crystal despecklers do not have mechanically deformable or moving elements that reduce the reliability and durability of operation, and are more compact and simple in design. A comparative table of characteristics of the most effective despecklers in which the speckle contrast is reduced to ten percent or less, with an indication of their advantages and disadvantages, is given.
{"title":"Methods and Devices of Speckle-Noise Suppression (Review)","authors":"I. Kompanets, N. Zalyapin","doi":"10.4236/opj.2020.1010023","DOIUrl":"https://doi.org/10.4236/opj.2020.1010023","url":null,"abstract":"Speckles in images formed by a laser beam are interference noise arising due to coherent nature of laser radiation. As the number of projection systems using laser light sources increases, new methods and devices appear for reducing the contrast of speckle-noise and thereby suppressing it. Taking into account the long-standing nature of the problem and the continuing relev-ance of its solution, this review discusses modern practical methods and de-vices—despecklers, used to reduce the speckle contrast and to achieve high quality of projected images. The review discusses the nature of the speckles appearance, considers their statistical properties, and describes the measurement of the speckle contrast. The requirements for despecklers are considered, the most important of which are speckle suppression efficiency, sim-plicity of design and compactness, low power consumption and low optical loss. The characteristics of different types of despecklers, including diffusers, devices based on electroactive polymers, optical waveguides, colloidal solutions and liquid crystals, as well as orthogonal phase matrices and diffraction gratings proposed as despeckers, are examined in detail. It is shown that despecklers with decorrelation of the phase front based on the mirror deformation and optical fiber have less light losses. Electro-optical-liquid crystal despecklers do not have mechanically deformable or moving elements that reduce the reliability and durability of operation, and are more compact and simple in design. A comparative table of characteristics of the most effective despecklers in which the speckle contrast is reduced to ten percent or less, with an indication of their advantages and disadvantages, is given.","PeriodicalId":64491,"journal":{"name":"光学与光子学期刊(英文)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70714275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. M. El-Nicklawy, A. Hassan, A. Elmahdy, A. Abd-Rabou, Ezzulddin Abdoulsahib Eesee
Under conditions differing from those subjected for central limit theorem, the spatial autocorrelation function of speckle pattern resulting from illuminated rough surface is investigated. Its dependence on different illuminating apertures and the average of the roughness heights is presented theoretically and experimentally. The experiments were carried out using a set of circular and square apertures having different sizes. The results indicate that, increasing the size of the illuminating aperture leads to a decrease in the width of the main lobe of the spatial autocorrelation function.
{"title":"Effect of the Illuminating Point Spread Function and Roughness on the Speckle Correlation Field","authors":"M. M. El-Nicklawy, A. Hassan, A. Elmahdy, A. Abd-Rabou, Ezzulddin Abdoulsahib Eesee","doi":"10.4236/opj.2019.911015","DOIUrl":"https://doi.org/10.4236/opj.2019.911015","url":null,"abstract":"Under conditions differing from those subjected for central limit theorem, the spatial autocorrelation function of speckle pattern resulting from illuminated rough surface is investigated. Its dependence on different illuminating apertures and the average of the roughness heights is presented theoretically and experimentally. The experiments were carried out using a set of circular and square apertures having different sizes. The results indicate that, increasing the size of the illuminating aperture leads to a decrease in the width of the main lobe of the spatial autocorrelation function.","PeriodicalId":64491,"journal":{"name":"光学与光子学期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46412205","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-11-01DOI: 10.1109/PHOTONICS49561.2019.00009
Wenfei Zhang, Yaoyao Ye
Optical networks-on-chips (NoCs) based on silicon photonics have been proposed as an emerging communication architecture for many-core chip multiprocessors. However, one of the key challenges is the thermal sensitivity of silicon photonic devices under on-chip temperature variations, which would result in significant thermal-induced optical power loss in optical NoCs. In this work, we propose an approximate Q-routing to find optimal low-loss paths in the presence of on-chip temperature variations. With the method of linear function approximation, the proposed approximate Q-routing does not require Q-tables which are necessary in traditional table-based Q-routing. Simulation results of an 8x8 mesh-based optical NoC under a set of synthetic traffic patterns and real applications show that the proposed approximate Q-routing can converge faster and its optimization effect is very close to the best optimization effect of the traditional table-based Q-routing.
{"title":"An Approximate Thermal-Aware Q-Routing for Optical NoCs","authors":"Wenfei Zhang, Yaoyao Ye","doi":"10.1109/PHOTONICS49561.2019.00009","DOIUrl":"https://doi.org/10.1109/PHOTONICS49561.2019.00009","url":null,"abstract":"Optical networks-on-chips (NoCs) based on silicon photonics have been proposed as an emerging communication architecture for many-core chip multiprocessors. However, one of the key challenges is the thermal sensitivity of silicon photonic devices under on-chip temperature variations, which would result in significant thermal-induced optical power loss in optical NoCs. In this work, we propose an approximate Q-routing to find optimal low-loss paths in the presence of on-chip temperature variations. With the method of linear function approximation, the proposed approximate Q-routing does not require Q-tables which are necessary in traditional table-based Q-routing. Simulation results of an 8x8 mesh-based optical NoC under a set of synthetic traffic patterns and real applications show that the proposed approximate Q-routing can converge faster and its optimization effect is very close to the best optimization effect of the traditional table-based Q-routing.","PeriodicalId":64491,"journal":{"name":"光学与光子学期刊(英文)","volume":"29 1","pages":"22-27"},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74004469","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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