We study the coupling of a finite number of Bloch surface waves (BSWs) propagating in different directions at the surface of a dielectric multilayer. These surface waves arise from a set of diffraction orders associated to a grating on the bottom surface of the substrate that is illuminated by a normally incident beam. Simultaneous excitation of multiple BSWs is possible with a set of diffraction orders having the same radial spatial frequency. Using rigorous electromagnetic theory, we design gratings for simultaneous excitation of two, four and six BSWs propagating in directions separated by π, π/2 and π/3 azimuthal intervals, respectively
{"title":"Multiple Bloch surface wave excitation with gratings","authors":"Lewis Asilevi","doi":"10.1051/jeos/2024007","DOIUrl":"https://doi.org/10.1051/jeos/2024007","url":null,"abstract":"We study the coupling of a finite number of Bloch surface waves (BSWs) propagating in different directions at the surface of a\u0000dielectric multilayer. These surface waves arise from a set of diffraction orders associated to a grating on the bottom surface of the substrate\u0000that is illuminated by a normally incident beam. Simultaneous excitation of multiple BSWs is possible with a set of diffraction orders having\u0000the same radial spatial frequency. Using rigorous electromagnetic theory, we design gratings for simultaneous excitation of two, four and six\u0000BSWs propagating in directions separated by π, π/2 and π/3 azimuthal intervals, respectively","PeriodicalId":674,"journal":{"name":"Journal of the European Optical Society-Rapid Publications","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2024-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140440333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 demonstrate the generation of broadband tunable and synchronized pulses exceeding the microjoule level using the new concept of fiber optical parametric chirped-pulse oscillation (FOPCPO). The oscillator is based on a collapsed-ends photonic crystal fiber pumped in the normal dispersion regime by an ytterbium fiber laser delivering highly-chirped pulses. The experimental results are compared with the results of numerical simulations and highlight that the feedback ratio appears as a key parameter for optimizing the system’s efficiency and dynamics.
{"title":"µJ-level normal-dispersion fiber optical chirped-pulse parametric oscillator","authors":"T. Guezennec","doi":"10.1051/jeos/2024006","DOIUrl":"https://doi.org/10.1051/jeos/2024006","url":null,"abstract":"We demonstrate the generation of broadband tunable and synchronized pulses exceeding the microjoule level using the new concept of fiber optical parametric chirped-pulse oscillation (FOPCPO). The oscillator is based on a collapsed-ends photonic crystal fiber pumped in the normal dispersion regime by an ytterbium fiber laser delivering highly-chirped pulses. The experimental results are compared with the results of numerical simulations and highlight that the feedback ratio appears as a key parameter for optimizing the system’s efficiency and dynamics.","PeriodicalId":674,"journal":{"name":"Journal of the European Optical Society-Rapid Publications","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2024-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139958350","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
A spectrophotometric method is demonstrated for refractive index and thickness determination of thin and ultrathin metallic films. The method involves a three-layer stack where the metallic layer of interest is deposited on an opaque Si wafer coated with SiO2. This stack creates oscillations in the reflectance spectrum, which are highly sensitive to the index of the metallic film, allowing precise determination of the index of layers down to 1nm. Experimental index values are given for Ag and Au over the wavelength range of 370-835nm. These results are correlated with AFM images of the films, which reveal dramatic changes in structure for layers of different thickness.
{"title":"Investigating Ultra-thin Ag and Au Layers Using Spectrophotometry and AFM Imaging","authors":"R. Shurvinton","doi":"10.1051/jeos/2024005","DOIUrl":"https://doi.org/10.1051/jeos/2024005","url":null,"abstract":"A spectrophotometric method is demonstrated for refractive index and thickness determination of thin and ultrathin metallic films. The method involves a three-layer stack where the metallic layer of interest is deposited on an opaque Si wafer coated with SiO2. This stack creates oscillations in the reflectance spectrum, which are highly sensitive to the index of the metallic film, allowing precise determination of the index of layers down to 1nm. Experimental index values are given for Ag and Au over the wavelength range of 370-835nm. These results are correlated with AFM images of the films, which reveal dramatic changes in structure for layers of different thickness.","PeriodicalId":674,"journal":{"name":"Journal of the European Optical Society-Rapid Publications","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2024-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139844108","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 analysis the noncollinear spontaneous parametric down conversion(SPDC) and compare the biphotons generated by the chirped quasi-phase-matching(QPM) between the periodically poled lithium niobate(PPLN) and periodically poled KTiOPO_4(PPKTP) crystals. Due to the chirping of the crystals, the frequency response range of the biphotons would be greatly increased. For nonlinear SPDC, angular variation is limited (less than 0.06 degree in this paper), and the angle would narrow the frequency response range of the biphotons. We compare the effect of angle in PPLN crystals and PPKTP crystals for biphotons. Both the two crystals with chirped QPM, the single-cycle biphotons can be generated during noncollinear SPDC within a suitable angle range, which is favorable for wider applications in experiments.
{"title":"The Single-Cycle Biphotons Generated by Noncollinear SPDC in The Chirped QPM Crystals","authors":"Jinbao Wang","doi":"10.1051/jeos/2024004","DOIUrl":"https://doi.org/10.1051/jeos/2024004","url":null,"abstract":"We analysis the noncollinear spontaneous parametric down conversion(SPDC) and compare the biphotons generated by the chirped quasi-phase-matching(QPM) between the periodically poled lithium niobate(PPLN) and periodically poled KTiOPO_4(PPKTP) crystals. Due to the chirping of the crystals, the frequency response range of the biphotons would be greatly increased. For nonlinear SPDC, angular variation is limited (less than 0.06 degree in this paper), and the angle would narrow the frequency response range of the biphotons. We compare the effect of angle in PPLN crystals and PPKTP crystals for biphotons. Both the two crystals with chirped QPM, the single-cycle biphotons can be generated during noncollinear SPDC within a suitable angle range, which is favorable for wider applications in experiments.","PeriodicalId":674,"journal":{"name":"Journal of the European Optical Society-Rapid Publications","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2024-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139783266","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
A spectrophotometric method is demonstrated for refractive index and thickness determination of thin and ultrathin metallic films. The method involves a three-layer stack where the metallic layer of interest is deposited on an opaque Si wafer coated with SiO2. This stack creates oscillations in the reflectance spectrum, which are highly sensitive to the index of the metallic film, allowing precise determination of the index of layers down to 1nm. Experimental index values are given for Ag and Au over the wavelength range of 370-835nm. These results are correlated with AFM images of the films, which reveal dramatic changes in structure for layers of different thickness.
{"title":"Investigating Ultra-thin Ag and Au Layers Using Spectrophotometry and AFM Imaging","authors":"R. Shurvinton","doi":"10.1051/jeos/2024005","DOIUrl":"https://doi.org/10.1051/jeos/2024005","url":null,"abstract":"A spectrophotometric method is demonstrated for refractive index and thickness determination of thin and ultrathin metallic films. The method involves a three-layer stack where the metallic layer of interest is deposited on an opaque Si wafer coated with SiO2. This stack creates oscillations in the reflectance spectrum, which are highly sensitive to the index of the metallic film, allowing precise determination of the index of layers down to 1nm. Experimental index values are given for Ag and Au over the wavelength range of 370-835nm. These results are correlated with AFM images of the films, which reveal dramatic changes in structure for layers of different thickness.","PeriodicalId":674,"journal":{"name":"Journal of the European Optical Society-Rapid Publications","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2024-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139784312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 analysis the noncollinear spontaneous parametric down conversion(SPDC) and compare the biphotons generated by the chirped quasi-phase-matching(QPM) between the periodically poled lithium niobate(PPLN) and periodically poled KTiOPO_4(PPKTP) crystals. Due to the chirping of the crystals, the frequency response range of the biphotons would be greatly increased. For nonlinear SPDC, angular variation is limited (less than 0.06 degree in this paper), and the angle would narrow the frequency response range of the biphotons. We compare the effect of angle in PPLN crystals and PPKTP crystals for biphotons. Both the two crystals with chirped QPM, the single-cycle biphotons can be generated during noncollinear SPDC within a suitable angle range, which is favorable for wider applications in experiments.
{"title":"The Single-Cycle Biphotons Generated by Noncollinear SPDC in The Chirped QPM Crystals","authors":"Jinbao Wang","doi":"10.1051/jeos/2024004","DOIUrl":"https://doi.org/10.1051/jeos/2024004","url":null,"abstract":"We analysis the noncollinear spontaneous parametric down conversion(SPDC) and compare the biphotons generated by the chirped quasi-phase-matching(QPM) between the periodically poled lithium niobate(PPLN) and periodically poled KTiOPO_4(PPKTP) crystals. Due to the chirping of the crystals, the frequency response range of the biphotons would be greatly increased. For nonlinear SPDC, angular variation is limited (less than 0.06 degree in this paper), and the angle would narrow the frequency response range of the biphotons. We compare the effect of angle in PPLN crystals and PPKTP crystals for biphotons. Both the two crystals with chirped QPM, the single-cycle biphotons can be generated during noncollinear SPDC within a suitable angle range, which is favorable for wider applications in experiments.","PeriodicalId":674,"journal":{"name":"Journal of the European Optical Society-Rapid Publications","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2024-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139843037","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
This work presents a complete Mueller matrix imaging polarimeter that uses three liquid-crystal retarders and a pixelated polarization camera. The polarimeter is characterized and optimized with a standard correction procedure here adapted to be performed fully in-situ, without any additional element, based on considering the polarization camera as the reference. The accuracy limit caused by the extinction ratio in the camera micro-polarizers is analyzed. Finally, the imaging polarimeter is tested experimentally by analyzing well-known samples for structured light applications such as patterned retarders, a patterned polarizer, and a liquid-crystal depolarizer. The work is presented in a tutorial style useful to reproduce the procedure by non-experts in polarimetry.
{"title":"Mueller matrix imaging polarimeter with polarization camera self-calibration applied to structured light components","authors":"María del Mar Sánchez-López","doi":"10.1051/jeos/2024003","DOIUrl":"https://doi.org/10.1051/jeos/2024003","url":null,"abstract":"This work presents a complete Mueller matrix imaging polarimeter that uses three liquid-crystal retarders and a pixelated polarization camera. The polarimeter is characterized and optimized with a standard correction procedure here adapted to be performed fully in-situ, without any additional element, based on considering the polarization camera as the reference. The accuracy limit caused by the extinction ratio in the camera micro-polarizers is analyzed. Finally, the imaging polarimeter is tested experimentally by analyzing well-known samples for structured light applications such as patterned retarders, a patterned polarizer, and a liquid-crystal depolarizer. The work is presented in a tutorial style useful to reproduce the procedure by non-experts in polarimetry.","PeriodicalId":674,"journal":{"name":"Journal of the European Optical Society-Rapid Publications","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2024-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139593318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Characterizing the number of sheets in a stack of paper typically involves mechanical separation of the individual sheets. Here, we explore an nondestructive method that can be applied to the intact paper stack. Namely, terahertz time-of-flight tomography, together with post signal-processing technique sparse deconvolution based on a two-step iterative shrinkage-thresholding algorithm (SD/TWIST), is employed to reconstruct the stratigraphy of stacks of sheets of paper with multilayered structure in a nondestructive and noncontact manner. The double-Gaussian mixture model (DGMM) is also incorporated to suppress dispersion in the reflected THz echoes. The effectiveness and accuracy of the proposed adaptive sparse-deconvolution method are verified experimentally and numerically. Compared with the commonly used frequency wavelet-domain deconvolution (FWDD) method and previous implementations of sparse deconvolution based on an iterative-shrinkage and thresholding algorithm (SD/IST), the proposed sparse-deconvolution approach can provide a clearer and rapid stratigraphic reconstruction of the paper stacks studied,while ensuring accurate thickness information for each paper sheet in the presence of noise, revealing the potential usage of real-time THz tomographic-image processing.
{"title":"Terahertz Nondestructive Stratigraphic Reconstruction of Paper Stacks Based on Adaptive Sparse Deconvolution","authors":"David Citrin","doi":"10.1051/jeos/2024001","DOIUrl":"https://doi.org/10.1051/jeos/2024001","url":null,"abstract":"Characterizing the number of sheets in a stack of paper typically involves mechanical separation of the individual sheets. Here, we explore an nondestructive method that can be applied to the intact paper stack. Namely, terahertz time-of-flight tomography, together with post signal-processing technique sparse deconvolution based on a two-step iterative shrinkage-thresholding algorithm (SD/TWIST), is employed to reconstruct the stratigraphy of stacks of sheets of paper with multilayered structure in a nondestructive and noncontact manner. The double-Gaussian mixture model (DGMM) is also incorporated to suppress dispersion in the reflected THz echoes. The effectiveness and accuracy of the proposed adaptive sparse-deconvolution method are verified experimentally and numerically. Compared with the commonly used frequency wavelet-domain deconvolution (FWDD) method and previous implementations of sparse deconvolution based on an iterative-shrinkage and thresholding algorithm (SD/IST), the proposed sparse-deconvolution approach can provide a clearer and rapid stratigraphic reconstruction of the paper stacks studied,while ensuring accurate thickness information for each paper sheet in the presence of noise, revealing the potential usage of real-time THz tomographic-image processing.","PeriodicalId":674,"journal":{"name":"Journal of the European Optical Society-Rapid Publications","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2024-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139612673","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Considering the serious risks posed by the heavy metals present in pig diets, monitoring and controlling the amount of these metals is crucial. The laser-induced breakdown spectroscopy (LIBS) is a promising technique for performing elemental analysis due to its unique advantages, such as rapid, in situ, nondestructive, and online detection of various minerals. In order to improve the detection accuracy and detection limit (LOD) of elements, the spatial constraint combined with laser-induced breakdown spectroscopy (CC-LIBS) is used to detect the quantity of zinc in pig feed and achieve the detection of samples with lower concentrations. Zn I 480.86 nm is selected as the characteristic spectral line, and the effects of different two-dimensional (cylindrical) and three-dimensional (hemispherical, truncated cone) cavities on the enhancement factor are compared under different. The results show that the optimal conditions include a circular constrained cavity D5H2, a delay time of 2.08, and an enhancement factor of 3.01 associated with the analytical spectral line. The detection limit of zinc in samples under CC-LIBS is 62.67 mg/kg (the recommended quantity of zinc in pig diet mentioned in the safe use of feed additives is 43-80 mg/kg), which is 35.65% lower than that under the LIBS (97.39 mg/kg). Therefore, this work provides a new test basis and idea for the detection of zinc in pig feed.
{"title":"Detection of zinc in pig feed based on the cavities of different shapes combined with LIBS","authors":"haung meng qin","doi":"10.1051/jeos/2023047","DOIUrl":"https://doi.org/10.1051/jeos/2023047","url":null,"abstract":"Considering the serious risks posed by the heavy metals present in pig diets, monitoring and controlling the amount of these metals is crucial. The laser-induced breakdown spectroscopy (LIBS) is a promising technique for performing elemental analysis due to its unique advantages, such as rapid, in situ, nondestructive, and online detection of various minerals. In order to improve the detection accuracy and detection limit (LOD) of elements, the spatial constraint combined with laser-induced breakdown spectroscopy (CC-LIBS) is used to detect the quantity of zinc in pig feed and achieve the detection of samples with lower concentrations. Zn I 480.86 nm is selected as the characteristic spectral line, and the effects of different two-dimensional (cylindrical) and three-dimensional (hemispherical, truncated cone) cavities on the enhancement factor are compared under different. The results show that the optimal conditions include a circular constrained cavity D5H2, a delay time of 2.08, and an enhancement factor of 3.01 associated with the analytical spectral line. The detection limit of zinc in samples under CC-LIBS is 62.67 mg/kg (the recommended quantity of zinc in pig diet mentioned in the safe use of feed additives is 43-80 mg/kg), which is 35.65% lower than that under the LIBS (97.39 mg/kg). Therefore, this work provides a new test basis and idea for the detection of zinc in pig feed.","PeriodicalId":674,"journal":{"name":"Journal of the European Optical Society-Rapid Publications","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2023-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138959369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 analysis the generation of entangled biphotons by symmetric and antisymmetric phase modulation to obtain the corresponding joint spectral amplitude functions(JSAF) during the spontaneous parametric down-conversion(SPDC). With the help of Schmidt decomposition, the distribution probabilities of different modes are analyzed and the degree of entanglement is improved, which in turn leads to the effective regulation of entanglement, entropy, Schmidt coefficient and Schmidt number. Through simulations, we find that the antisymmetric phase modulation can slightly broaden the spectrum width, and the symmetric phase modulation distribution is more advantageous when the crystal is shorter.
{"title":"The Symmetric and Antisymmetric Phase Modulation for the Joint Spectral Amplitude of the Biphotons in SPDC","authors":"Jinbao Wang","doi":"10.1051/jeos/2023046","DOIUrl":"https://doi.org/10.1051/jeos/2023046","url":null,"abstract":"We analysis the generation of entangled biphotons by symmetric and antisymmetric phase modulation to obtain the corresponding joint spectral amplitude functions(JSAF) during the spontaneous parametric down-conversion(SPDC). With the help of Schmidt decomposition, the distribution probabilities of different modes are analyzed and the degree of entanglement is improved, which in turn leads to the effective regulation of entanglement, entropy, Schmidt coefficient and Schmidt number. Through simulations, we find that the antisymmetric phase modulation can slightly broaden the spectrum width, and the symmetric phase modulation distribution is more advantageous when the crystal is shorter.","PeriodicalId":674,"journal":{"name":"Journal of the European Optical Society-Rapid Publications","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2023-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138584296","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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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