In this paper, we present a real and simulated study of a frequency up mixing employing an electro-optical sampling semiconductor optical amplifier Mach–Zehnder interferometer (SOA–MZI) along with the differential modulation schema. The sampling signal is generated by an optical pulse clock (OPC) at a frequency of fs= 19.5 GHz. The quadratic phase shift keying (QPSK) signal at an intermediate frequency (IF) fIF is shifted to high frequencies nfs ± fIF at the SOA–MZI output. Using a simulator entitled Virtual Photonics Inc. (VPI), we generate sampled QPSK signals and analyze their merits during conversion gains and error vector magnitudes (EVMs). We conducted simulations of mixing in the SOA–MZI operating in a high-frequency band up to 195.5 GHz. The positive conversion gain is accomplished over the mixing frequencies. The EVM is used to evaluate the performance of the electro-optical sampling up-convertor. The EVM reaches 14% at a data rate of 5 Gbit/s at 195.5 GHz. During the experimental work, the results obtained in simulations are set side by side with the factual ones in the frequency range up to 59 GHz. Thus, the comparison between them confirms that they have approximately the same performance.
{"title":"Frequency Alteration Built on an Electro-Optical Sampling SOA–MZI Using a Differential Modulation Schema","authors":"Hassan Termos, A. Mansour","doi":"10.3390/opt3030022","DOIUrl":"https://doi.org/10.3390/opt3030022","url":null,"abstract":"In this paper, we present a real and simulated study of a frequency up mixing employing an electro-optical sampling semiconductor optical amplifier Mach–Zehnder interferometer (SOA–MZI) along with the differential modulation schema. The sampling signal is generated by an optical pulse clock (OPC) at a frequency of fs= 19.5 GHz. The quadratic phase shift keying (QPSK) signal at an intermediate frequency (IF) fIF is shifted to high frequencies nfs ± fIF at the SOA–MZI output. Using a simulator entitled Virtual Photonics Inc. (VPI), we generate sampled QPSK signals and analyze their merits during conversion gains and error vector magnitudes (EVMs). We conducted simulations of mixing in the SOA–MZI operating in a high-frequency band up to 195.5 GHz. The positive conversion gain is accomplished over the mixing frequencies. The EVM is used to evaluate the performance of the electro-optical sampling up-convertor. The EVM reaches 14% at a data rate of 5 Gbit/s at 195.5 GHz. During the experimental work, the results obtained in simulations are set side by side with the factual ones in the frequency range up to 59 GHz. Thus, the comparison between them confirms that they have approximately the same performance.","PeriodicalId":54548,"journal":{"name":"Progress in Optics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76605974","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Federica Pappalardo, Francisco Romero Romero Lairado, C. L. D. Louis de Canonville, C. Martin, G. Giacometti, Guillaume Serin, E. Salomon, T. Angot, L. Gallais, R. Bisson, M. Minissale
Tungsten (W) is the material selected for the divertor exhaust of the international nuclear fusion experiment ITER. In this harsh environment, the interactions of heat loads and ion fluxes with W can induce temporary or permanent evolution in the optical properties. Poor knowledge of such evolution during a plasma operation can lead to errors in temperature measurements performed by optical diagnostics. Therefore, it is of fundamental importance to characterize possible changes in W optical properties. In this work, we studied the role of morphology and temperature on the optical response of W. The reflectivities of five W samples with different roughness values (20–100 nm) were measured during laser annealing (25–800 °C) in the visible and near-infrared domains (500–1100 nm). We observed an increase in reflectivity after annealing and we demonstrated that it was due to a change in the chemical composition of the surface, in particular a reduction in the amount of native oxide. Moreover, we show that roughness does not sensibly vary in the investigated temperature range. By highlighting the role played by roughness and surface impurities (e.g., oxide), we provide insight in how W optical properties can evolve in tokamaks where high ion fluxes, heat loads, and impurities can induce the evolution of both the morphology and surface composition of W.
{"title":"Optical Properties of Tungsten: A Parametric Study to Characterize the Role of Roughness, Surface Composition and Temperature","authors":"Federica Pappalardo, Francisco Romero Romero Lairado, C. L. D. Louis de Canonville, C. Martin, G. Giacometti, Guillaume Serin, E. Salomon, T. Angot, L. Gallais, R. Bisson, M. Minissale","doi":"10.3390/opt3030021","DOIUrl":"https://doi.org/10.3390/opt3030021","url":null,"abstract":"Tungsten (W) is the material selected for the divertor exhaust of the international nuclear fusion experiment ITER. In this harsh environment, the interactions of heat loads and ion fluxes with W can induce temporary or permanent evolution in the optical properties. Poor knowledge of such evolution during a plasma operation can lead to errors in temperature measurements performed by optical diagnostics. Therefore, it is of fundamental importance to characterize possible changes in W optical properties. In this work, we studied the role of morphology and temperature on the optical response of W. The reflectivities of five W samples with different roughness values (20–100 nm) were measured during laser annealing (25–800 °C) in the visible and near-infrared domains (500–1100 nm). We observed an increase in reflectivity after annealing and we demonstrated that it was due to a change in the chemical composition of the surface, in particular a reduction in the amount of native oxide. Moreover, we show that roughness does not sensibly vary in the investigated temperature range. By highlighting the role played by roughness and surface impurities (e.g., oxide), we provide insight in how W optical properties can evolve in tokamaks where high ion fluxes, heat loads, and impurities can induce the evolution of both the morphology and surface composition of W.","PeriodicalId":54548,"journal":{"name":"Progress in Optics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75821856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Multipartite quantum key distribution (QKD) is a promising area of quantum networks that provides unconditional secret keys among multiple parties, enabling only legitimate users to decrypt the encrypted message. However, security proofs of existing multipartite QKD typically assume perfect state preparation devices of legitimate users and neglect the relative rotation of reference frames. These presumptions are, nevertheless, very difficult to meet in practice, and thus the security of current multipartite QKD implementations is not guaranteed. By combining the idea of a loss tolerant technique, introduced by Tamaki et al. (K. Tamaki et al., Phys. Rev. A, 90, 052314, 2014), and the concept of a reference frame-independent protocol, we propose a three-party QKD protocol that considers state preparation flaws and the slow drift of reference frames. Through a numerical simulation, the influence of misaliged reference frames on the protocol’s stability was examined by drifting reference frames through angles β=π/5, β=π/6 and β=π/7. In addition, the performance of the proposed protocol was examined for the encoding flaws set at δ=0.35, δ=0.20, and δ=0.10. The results show that the protocol is robust against state preparation flaws, and is insignificantly impacted by misalignment of the reference frames because the achieved transmission distances and secret key rates are comparable to the perfect scenarios. This work dramatically contributes toward the realization of practical and secure multipartite QKD. The proposed protocol has direct applications in quantum communication network environments that involve unknown and slowly varying reference frames, web conferences, and online communications.
多方量子密钥分发(QKD)是量子网络中一个很有前途的领域，它在多方之间提供无条件的秘密密钥，使只有合法用户才能解密加密的消息。然而，现有的多方QKD安全证明通常假设合法用户的完美状态准备设备，忽略了参照系的相对旋转。然而，这些假设在实践中很难满足，因此当前多方QKD实现的安全性得不到保证。通过结合Tamaki et al. (K. Tamaki et al.， Phys.)提出的损失容忍技术的思想。Rev. A, 90, 052314, 2014)，以及参考帧无关协议的概念，我们提出了一个考虑状态准备缺陷和参考帧缓慢漂移的三方QKD协议。通过数值模拟，通过β=π/5、β=π/6和β=π/7角度漂移参考系，考察了失调参考系对协议稳定性的影响。此外，在δ=0.35， δ=0.20和δ=0.10的编码缺陷设置下，测试了所提出协议的性能。结果表明，该协议对状态准备缺陷具有鲁棒性，并且由于实现的传输距离和密钥速率与完美场景相当，因此受参考帧不对齐的影响不大。这项工作为实现实用和安全的多方QKD做出了巨大贡献。所提出的协议在涉及未知和缓慢变化的参考帧、网络会议和在线通信的量子通信网络环境中具有直接应用。
{"title":"Tripartite Quantum Key Distribution Implemented with Imperfect Sources","authors":"Comfort Sekga, M. Mafu","doi":"10.3390/opt3030019","DOIUrl":"https://doi.org/10.3390/opt3030019","url":null,"abstract":"Multipartite quantum key distribution (QKD) is a promising area of quantum networks that provides unconditional secret keys among multiple parties, enabling only legitimate users to decrypt the encrypted message. However, security proofs of existing multipartite QKD typically assume perfect state preparation devices of legitimate users and neglect the relative rotation of reference frames. These presumptions are, nevertheless, very difficult to meet in practice, and thus the security of current multipartite QKD implementations is not guaranteed. By combining the idea of a loss tolerant technique, introduced by Tamaki et al. (K. Tamaki et al., Phys. Rev. A, 90, 052314, 2014), and the concept of a reference frame-independent protocol, we propose a three-party QKD protocol that considers state preparation flaws and the slow drift of reference frames. Through a numerical simulation, the influence of misaliged reference frames on the protocol’s stability was examined by drifting reference frames through angles β=π/5, β=π/6 and β=π/7. In addition, the performance of the proposed protocol was examined for the encoding flaws set at δ=0.35, δ=0.20, and δ=0.10. The results show that the protocol is robust against state preparation flaws, and is insignificantly impacted by misalignment of the reference frames because the achieved transmission distances and secret key rates are comparable to the perfect scenarios. This work dramatically contributes toward the realization of practical and secure multipartite QKD. The proposed protocol has direct applications in quantum communication network environments that involve unknown and slowly varying reference frames, web conferences, and online communications.","PeriodicalId":54548,"journal":{"name":"Progress in Optics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74134743","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In nanoscale photonic devices, the demand for multifunctionality from 2D metasurface optics has increased rapidly. To explore the required fine-tuning in the design metrics, we reinvestigated the trapezoid-shape copper metasurface using finite-difference time-domain simulation to efficiently utilize linearly polarized light for two different functionalities. From the plasmonic band structure, we could see how the degree of asymmetry in the geometry affected the efficient resonance coupling of the traveling plasmonic modes, along with the different types of mode hybridization profiles that were related to the nanoantenna’s geometric shape. By tuning the nanoantenna’s length, we could excite the effective plasmon mode that was supported by this configuration and guide surface waves unidirectionally from the normal incidence free-space light within the visible to infrared range. The directed surface plasmon polaritons had both antisymmetric and symmetric modes that oscillated between the top and bottom surfaces of the continuous metal layer, depending on the nanoantenna’s length and wavelength. This proposed copper metasurface was optimized for a far-field application of broadband (600–900 nm) anomalous beam steering for an average of 60% efficiency with a maximum angle of 64°. This work offers more understanding of a metasurface being implemented in small plasmonic devices, waveguide mode controlling and beam steering with wavelength-dependent functionalities.
{"title":"Coupled Plasmon Wave Dynamics beyond Anomalous Reflection: A Phase Gradient Copper Metasurface for the Visible to Near-Infrared Spectrum","authors":"H. Sultana","doi":"10.3390/opt3030024","DOIUrl":"https://doi.org/10.3390/opt3030024","url":null,"abstract":"In nanoscale photonic devices, the demand for multifunctionality from 2D metasurface optics has increased rapidly. To explore the required fine-tuning in the design metrics, we reinvestigated the trapezoid-shape copper metasurface using finite-difference time-domain simulation to efficiently utilize linearly polarized light for two different functionalities. From the plasmonic band structure, we could see how the degree of asymmetry in the geometry affected the efficient resonance coupling of the traveling plasmonic modes, along with the different types of mode hybridization profiles that were related to the nanoantenna’s geometric shape. By tuning the nanoantenna’s length, we could excite the effective plasmon mode that was supported by this configuration and guide surface waves unidirectionally from the normal incidence free-space light within the visible to infrared range. The directed surface plasmon polaritons had both antisymmetric and symmetric modes that oscillated between the top and bottom surfaces of the continuous metal layer, depending on the nanoantenna’s length and wavelength. This proposed copper metasurface was optimized for a far-field application of broadband (600–900 nm) anomalous beam steering for an average of 60% efficiency with a maximum angle of 64°. This work offers more understanding of a metasurface being implemented in small plasmonic devices, waveguide mode controlling and beam steering with wavelength-dependent functionalities.","PeriodicalId":54548,"journal":{"name":"Progress in Optics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80528692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rongkuan Leng, Zhi Wang, Chao Fang, Lei Liu, Zhiwei Chen, Xinxu Cui
In many optical engineering applications, a spherical cap shaped optical element is widely used such as concave or convex mirrors in reflective optics. Such an element can also tilt around the vertex which corresponds to an off-axis optical design. The optical backscattering of such an optical element sometimes could be important. For example, in the space-based gravitational wave detection, the backscattering of such an element could be superimposed with the local oscillator and limits the sensitivity of the spacecraft. The scattered contributions depend on the scattering property of the mirror surfaces and the geometrical arrangement including the radius of curvature, the tilt and the interval between the scattering source and detector plane. Based on random estimation method, this paper starts from the radiometry, combines these variables and calculates the theoretical amount of back scattered light for both diffuse and superpolished surfaces. The results are compared with analytical and ray tracing solution. The conclusions can be used to further improve the optical design of the telescope or extended to other cases where the backscattered light should be controlled.
{"title":"Backscattering Estimation of a Tilted Spherical Cap for Different Kinds of Optical Scattering","authors":"Rongkuan Leng, Zhi Wang, Chao Fang, Lei Liu, Zhiwei Chen, Xinxu Cui","doi":"10.3390/opt3020018","DOIUrl":"https://doi.org/10.3390/opt3020018","url":null,"abstract":"In many optical engineering applications, a spherical cap shaped optical element is widely used such as concave or convex mirrors in reflective optics. Such an element can also tilt around the vertex which corresponds to an off-axis optical design. The optical backscattering of such an optical element sometimes could be important. For example, in the space-based gravitational wave detection, the backscattering of such an element could be superimposed with the local oscillator and limits the sensitivity of the spacecraft. The scattered contributions depend on the scattering property of the mirror surfaces and the geometrical arrangement including the radius of curvature, the tilt and the interval between the scattering source and detector plane. Based on random estimation method, this paper starts from the radiometry, combines these variables and calculates the theoretical amount of back scattered light for both diffuse and superpolished surfaces. The results are compared with analytical and ray tracing solution. The conclusions can be used to further improve the optical design of the telescope or extended to other cases where the backscattered light should be controlled.","PeriodicalId":54548,"journal":{"name":"Progress in Optics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87894026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Briant, S. Krenek, Andrea Cupertino, F. Loubar, R. Braive, L. Weituschat, Daniel Ramos, M. J. Martin, P. Postigo, Alberto Casas, R. Eisermann, D. Schmid, Shahin Tabandeh, O. Hahtela, Sara Pourjamal, O. Kozlova, S. Kroker, W. Dickmann, L. Zimmermann, G. Winzer, T. Martel, P. Steeneken, R. Norte, S. Briaudeau
Temperature is one of the most relevant physical quantities that affects almost all processes in nature. However, the realization of accurate temperature standards using current temperature references, like the triple point of water, is difficult due to the requirements on material purity and stability of the environment. In addition, in harsh environments, current temperature sensors with electrical readout, like platinum resistors, are difficult to implement, urging the development of optical temperature sensors. In 2018, the European consortium Photoquant, consisting of metrological institutes and academic partners, started investigating new temperature standards for self-calibrated, embedded optomechanical sensor applications, as well as optimised high resolution and high reliability photonic sensors, to measure temperature at the nano and meso-scales and as a possible replacement for the standard platinum resistant thermometers. This article presents an overview of the results obtained with sensor prototypes that exploit photonic and optomechanical techniques for sensing temperatures over a large temperature range (5 K to 300 K). Different concepts are demonstrated, including ring resonators, ladder-like resonators and suspended membrane optomechanical thermometers, highlighting initial performance and challenges, like self-heating that need to be overcome to realize photonic and optomechanical thermometry applications.
{"title":"Photonic and Optomechanical Thermometry","authors":"T. Briant, S. Krenek, Andrea Cupertino, F. Loubar, R. Braive, L. Weituschat, Daniel Ramos, M. J. Martin, P. Postigo, Alberto Casas, R. Eisermann, D. Schmid, Shahin Tabandeh, O. Hahtela, Sara Pourjamal, O. Kozlova, S. Kroker, W. Dickmann, L. Zimmermann, G. Winzer, T. Martel, P. Steeneken, R. Norte, S. Briaudeau","doi":"10.3390/opt3020017","DOIUrl":"https://doi.org/10.3390/opt3020017","url":null,"abstract":"Temperature is one of the most relevant physical quantities that affects almost all processes in nature. However, the realization of accurate temperature standards using current temperature references, like the triple point of water, is difficult due to the requirements on material purity and stability of the environment. In addition, in harsh environments, current temperature sensors with electrical readout, like platinum resistors, are difficult to implement, urging the development of optical temperature sensors. In 2018, the European consortium Photoquant, consisting of metrological institutes and academic partners, started investigating new temperature standards for self-calibrated, embedded optomechanical sensor applications, as well as optimised high resolution and high reliability photonic sensors, to measure temperature at the nano and meso-scales and as a possible replacement for the standard platinum resistant thermometers. This article presents an overview of the results obtained with sensor prototypes that exploit photonic and optomechanical techniques for sensing temperatures over a large temperature range (5 K to 300 K). Different concepts are demonstrated, including ring resonators, ladder-like resonators and suspended membrane optomechanical thermometers, highlighting initial performance and challenges, like self-heating that need to be overcome to realize photonic and optomechanical thermometry applications.","PeriodicalId":54548,"journal":{"name":"Progress in Optics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88528823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Tang, Jianping Peng, Jinlong Li, Y. Wan, Xingzi Liu, Ruyu Ma
With the development of rail transit in terms of speed and carrying capacity, train safety problems caused by wheel tread defects and wear have become more prominent. The wheel is an important part of the train, and the wear and defects of the wheel tread are directly related to the safety of the train; therefore, wheel tread testing is a key element of train testing. In phase measuring profilometry (PMP), the virtual sine grating generated by the computer is projected onto the measured wheel tread by a digital projector, and then a camera is used to obtain the modulated deformed grating on the surface of the wheel tread. Next, the wrapped phase is obtained by the improved Stoilov algorithm, and the unwrapped phase is obtained by the phase unwrapped algorithm. Finally, the three-dimensional (3D) profile of the wheel tread is reconstructed. This paper presents an improved Stoilov algorithm based on probability and statistics. Supposing that the probability of real data was the highest, we chose the cosine square matrix value of the phase shift for processing. After ruling out the singular points of large error, we obtained the closest value to the true phase shift using the method of probability and statistics. The experimental results show that this method can effectively restrain the singular phenomenon, and the 3D profile of wheel tread can be reconstructed successfully.
{"title":"Wheel Tread Reconstruction Based on Improved Stoilov Algorithm","authors":"T. Tang, Jianping Peng, Jinlong Li, Y. Wan, Xingzi Liu, Ruyu Ma","doi":"10.3390/opt3020016","DOIUrl":"https://doi.org/10.3390/opt3020016","url":null,"abstract":"With the development of rail transit in terms of speed and carrying capacity, train safety problems caused by wheel tread defects and wear have become more prominent. The wheel is an important part of the train, and the wear and defects of the wheel tread are directly related to the safety of the train; therefore, wheel tread testing is a key element of train testing. In phase measuring profilometry (PMP), the virtual sine grating generated by the computer is projected onto the measured wheel tread by a digital projector, and then a camera is used to obtain the modulated deformed grating on the surface of the wheel tread. Next, the wrapped phase is obtained by the improved Stoilov algorithm, and the unwrapped phase is obtained by the phase unwrapped algorithm. Finally, the three-dimensional (3D) profile of the wheel tread is reconstructed. This paper presents an improved Stoilov algorithm based on probability and statistics. Supposing that the probability of real data was the highest, we chose the cosine square matrix value of the phase shift for processing. After ruling out the singular points of large error, we obtained the closest value to the true phase shift using the method of probability and statistics. The experimental results show that this method can effectively restrain the singular phenomenon, and the 3D profile of wheel tread can be reconstructed successfully.","PeriodicalId":54548,"journal":{"name":"Progress in Optics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87237576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Correlation plenoptic imaging (CPI) is an optical imaging technique based on intensity correlation measurement, which enables detecting, within fundamental physical limits, both the spatial distribution and the direction of light in a scene. This provides the possibility to perform tasks such as three-dimensional reconstruction and refocusing of different planes. Compared with standard plenoptic imaging devices, based on direct intensity measurement, CPI overcomes the problem of the strong trade-off between spatial and directional resolution. Here, we study the resolution limit in a recent development of the technique, called correlation plenoptic imaging between arbitrary planes (CPI-AP). The analysis, based on Gaussian test objects, highlights the main properties of the technique, as compared with standard imaging, and provides an analytical guideline to identify the limits at which an object can be considered resolved.
{"title":"Resolution Limit of Correlation Plenoptic Imaging between Arbitrary Planes","authors":"F. Scattarella, M. D’Angelo, F. Pepe","doi":"10.3390/opt3020015","DOIUrl":"https://doi.org/10.3390/opt3020015","url":null,"abstract":"Correlation plenoptic imaging (CPI) is an optical imaging technique based on intensity correlation measurement, which enables detecting, within fundamental physical limits, both the spatial distribution and the direction of light in a scene. This provides the possibility to perform tasks such as three-dimensional reconstruction and refocusing of different planes. Compared with standard plenoptic imaging devices, based on direct intensity measurement, CPI overcomes the problem of the strong trade-off between spatial and directional resolution. Here, we study the resolution limit in a recent development of the technique, called correlation plenoptic imaging between arbitrary planes (CPI-AP). The analysis, based on Gaussian test objects, highlights the main properties of the technique, as compared with standard imaging, and provides an analytical guideline to identify the limits at which an object can be considered resolved.","PeriodicalId":54548,"journal":{"name":"Progress in Optics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73210633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bicheng Guo, Boyang Zhang, Xiaowan Zheng, Siyuan Fang, Yue Fang, Bernard Sia, Lianxiang Yang
Shearography is a coherent optical technique that allows the identification of the first derivative of deformation in the shearing direction. Due to direct measuring strain information, shearography is suited for non-destructive testing and evaluation (NDT/NDE). However, if there is a small defect parallel to the shearing direction, the first derivative of deformation in the direction has no noticeable change, and the defect is not visible. Therefore, the development of a shearography system with dual-directional simultaneous measurement of the first derivatives of deformation both in x- and y-directions is highly demanded in the field of NDT/NDE. It is suited to inspect complicated defects, such as long and narrow slots, microcracks, etc. This paper presents a review of shearography for different dual-directional systems developed in the last two decades. After a brief overview of shearography, the paper will display two dual-directional shearographic techniques—temporal phase-shift (TPS) and spatial phase-shift (SPS) methods. TPS dual-shearing systems are suited for static measurements, while the SPS dual-shearing systems are useful for dynamic measurements. The basic theories, optical layouts, and comparisons are presented. The advantages and disadvantages of practical applications are discussed.
{"title":"Review of Shearography for Dual-Directional Measurement","authors":"Bicheng Guo, Boyang Zhang, Xiaowan Zheng, Siyuan Fang, Yue Fang, Bernard Sia, Lianxiang Yang","doi":"10.3390/opt3020014","DOIUrl":"https://doi.org/10.3390/opt3020014","url":null,"abstract":"Shearography is a coherent optical technique that allows the identification of the first derivative of deformation in the shearing direction. Due to direct measuring strain information, shearography is suited for non-destructive testing and evaluation (NDT/NDE). However, if there is a small defect parallel to the shearing direction, the first derivative of deformation in the direction has no noticeable change, and the defect is not visible. Therefore, the development of a shearography system with dual-directional simultaneous measurement of the first derivatives of deformation both in x- and y-directions is highly demanded in the field of NDT/NDE. It is suited to inspect complicated defects, such as long and narrow slots, microcracks, etc. This paper presents a review of shearography for different dual-directional systems developed in the last two decades. After a brief overview of shearography, the paper will display two dual-directional shearographic techniques—temporal phase-shift (TPS) and spatial phase-shift (SPS) methods. TPS dual-shearing systems are suited for static measurements, while the SPS dual-shearing systems are useful for dynamic measurements. The basic theories, optical layouts, and comparisons are presented. The advantages and disadvantages of practical applications are discussed.","PeriodicalId":54548,"journal":{"name":"Progress in Optics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75280966","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We introduce a holographic wide angle system that combines the accuracy of a long focal length with the extended field of view of a wide angle lens. To accomplish this, we use a computer-generated hologram (CGH) in front of the lens to diffract light from (a discrete number of) specific angular locations. This method is tested in laboratory conditions, as well as under real-world conditions. This measurement system was developed as a possible tool for real-time movement tracking and control of extended dynamic structures, such as bridges and high-rise buildings. Within that application, the obtained measurement uncertainty is 10 μm in object space at 10 m distance spanning 10 m width.
{"title":"Holographic Wide-Angle System for Deformation Measurement of Extended Structures","authors":"Flavio Guerra, P. Wilhelm, T. Haist","doi":"10.3390/opt3010010","DOIUrl":"https://doi.org/10.3390/opt3010010","url":null,"abstract":"We introduce a holographic wide angle system that combines the accuracy of a long focal length with the extended field of view of a wide angle lens. To accomplish this, we use a computer-generated hologram (CGH) in front of the lens to diffract light from (a discrete number of) specific angular locations. This method is tested in laboratory conditions, as well as under real-world conditions. This measurement system was developed as a possible tool for real-time movement tracking and control of extended dynamic structures, such as bridges and high-rise buildings. Within that application, the obtained measurement uncertainty is 10 μm in object space at 10 m distance spanning 10 m width.","PeriodicalId":54548,"journal":{"name":"Progress in Optics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80701109","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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