Timofey Sergeev, Alexander Zyablovsky, E. Andrianov, Yurii Lozovik
An ultra-strong coupling regime takes place in a compound system when a coupling strength between the subsystems exceeds one-tenth of the system eigenfrequency. It transforms into a deep-strong coupling regime when the coupling strength exceeds the system eigenfrequency. In these regimes, there are difficulties with the description of relaxation processes without explicit consideration of environmental degrees of freedom. To correctly evaluate the relaxation rates, it is necessary to consider the interaction of the system with its environment taking into account the counter-rotating wave and diamagnetic terms. We develop a self-consistent theory for the calculation of the relaxation rates in the systems, in which the coupling strength is of the order of the system eigenfrequency. We demonstrate that the increase in the coupling strength can lead to a significant decrease in the relaxation rates. In particular, we show that, for frequency-independent density of states of the environment, the relaxation rates decrease exponentially with the increase in the coupling strength. This fact can be used to suppress losses by tuning the strength coupling and the environment states.
{"title":"Self-consistent description of relaxation processes in systems with ultra- and deep-strong coupling","authors":"Timofey Sergeev, Alexander Zyablovsky, E. Andrianov, Yurii Lozovik","doi":"10.1364/josab.501199","DOIUrl":"https://doi.org/10.1364/josab.501199","url":null,"abstract":"An ultra-strong coupling regime takes place in a compound system when a coupling strength between the subsystems exceeds one-tenth of the system eigenfrequency. It transforms into a deep-strong coupling regime when the coupling strength exceeds the system eigenfrequency. In these regimes, there are difficulties with the description of relaxation processes without explicit consideration of environmental degrees of freedom. To correctly evaluate the relaxation rates, it is necessary to consider the interaction of the system with its environment taking into account the counter-rotating wave and diamagnetic terms. We develop a self-consistent theory for the calculation of the relaxation rates in the systems, in which the coupling strength is of the order of the system eigenfrequency. We demonstrate that the increase in the coupling strength can lead to a significant decrease in the relaxation rates. In particular, we show that, for frequency-independent density of states of the environment, the relaxation rates decrease exponentially with the increase in the coupling strength. This fact can be used to suppress losses by tuning the strength coupling and the environment states.","PeriodicalId":17280,"journal":{"name":"Journal of The Optical Society of America B-optical Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135647980","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}
Sambuddha Majumder, Krishnanunni A, Sooraj Ravindran
GaAs/AlGaAs based nanowires are promising candidates for photovoltaic applications due to their high absorption coefficient, low surface reflection, and efficient collection of photogenerated carriers. This study focuses on optimizing the performance of p-i-n GaAs/AlGaAs nanowire solar cell arrays having a radial junction using optoelectronic simulations. The research investigates the optimal doping for the GaAs core and AlGaAs shell, as well as the impact of shell thickness and junction positions on solar cell performance. Additionally, the study examines the effect of various surface effects, including the presence of surface traps, surface recombination velocities, and associated lifetime degradation. Our studies find that a high doping density for the shell and core region is crucial for achieving an appropriate band configuration and carrier extraction. It also highlights that having a larger doping density is more important than having a larger lifetime. Finally, the research examines the effect of different aluminum compositions on photogeneration inside the nanowire and shows that having a high aluminum composition can confine most photogeneration to inner GaAs regions, potentially allowing for thicker AlGaAs shells, which can efficiently prevent surface recombination.
{"title":"Optimization of p-i-n GaAs/AlGaAs Heterojunction Nanowire Solar Cell for Improved Optical and Electrical Properties","authors":"Sambuddha Majumder, Krishnanunni A, Sooraj Ravindran","doi":"10.1364/josab.492196","DOIUrl":"https://doi.org/10.1364/josab.492196","url":null,"abstract":"GaAs/AlGaAs based nanowires are promising candidates for photovoltaic applications due to their high absorption coefficient, low surface reflection, and efficient collection of photogenerated carriers. This study focuses on optimizing the performance of p-i-n GaAs/AlGaAs nanowire solar cell arrays having a radial junction using optoelectronic simulations. The research investigates the optimal doping for the GaAs core and AlGaAs shell, as well as the impact of shell thickness and junction positions on solar cell performance. Additionally, the study examines the effect of various surface effects, including the presence of surface traps, surface recombination velocities, and associated lifetime degradation. Our studies find that a high doping density for the shell and core region is crucial for achieving an appropriate band configuration and carrier extraction. It also highlights that having a larger doping density is more important than having a larger lifetime. Finally, the research examines the effect of different aluminum compositions on photogeneration inside the nanowire and shows that having a high aluminum composition can confine most photogeneration to inner GaAs regions, potentially allowing for thicker AlGaAs shells, which can efficiently prevent surface recombination.","PeriodicalId":17280,"journal":{"name":"Journal of The Optical Society of America B-optical Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135132144","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}
In this work we compute, via the quantum potential approach, the Hamiltonian system determined by Hermite–Gaussian beams. Then we show that the integral curves of the Poynting vector, exact optics energy trajectories, conform to a subset of solutions to the corresponding Hamilton equations lying on hyperboloidal surfaces. The geometrical light rays associated with these beams are given by the tangent lines to the integral curves of the Poynting vector at the zeroes of the quantum potential, and the caustic region coincides with the zeroes of quantum potential and quantum force. One of the main contributions of this work is to present the relationship between the physical phase k Φ, the geometrical-optics phase k Φ G , and the quantum potential Q HG in the Hermite–Gaussian beams. Furthermore, note that for any solution to the paraxial wave equation in free space, the tangent lines to the integral curves of the Poynting vector that correspond to the geometric light rays are those that pass through the points where the region determined by zeroes of the quantum potential is tangent to the geometrical caustic determined by the geometric light rays .
{"title":"Properties of the Hermite-Gaussian beams via the quantum potential","authors":"Gilberto Silva-Ortigoza, Ernesto Ramos, EDNA GOCHICOA-FUENTES, Ramón Silva-Ortigoza","doi":"10.1364/josab.499272","DOIUrl":"https://doi.org/10.1364/josab.499272","url":null,"abstract":"In this work we compute, via the quantum potential approach, the Hamiltonian system determined by Hermite–Gaussian beams. Then we show that the integral curves of the Poynting vector, exact optics energy trajectories, conform to a subset of solutions to the corresponding Hamilton equations lying on hyperboloidal surfaces. The geometrical light rays associated with these beams are given by the tangent lines to the integral curves of the Poynting vector at the zeroes of the quantum potential, and the caustic region coincides with the zeroes of quantum potential and quantum force. One of the main contributions of this work is to present the relationship between the physical phase k Φ, the geometrical-optics phase k Φ G , and the quantum potential Q HG in the Hermite–Gaussian beams. Furthermore, note that for any solution to the paraxial wave equation in free space, the tangent lines to the integral curves of the Poynting vector that correspond to the geometric light rays are those that pass through the points where the region determined by zeroes of the quantum potential is tangent to the geometrical caustic determined by the geometric light rays .","PeriodicalId":17280,"journal":{"name":"Journal of The Optical Society of America B-optical Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135131848","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}
Mei Qiao, Tie-Jun Wang, Yong Liu, Tao Liu, Zhenxing Wang, Wanling Cui, Xiaoxin Wang, Xin Li, shicai xu
The (La, Sr)(Al, Ta)O 3 crystal was irradiated via 20.0 MeV C ion with fluence of 1.0×10 15 ions/cm 2 . The Rutherford backscattering (RBS)/channeling spectra, the hardness and elastic modulus as continuous functions of the depth, and X-ray diffraction (XRD) are used to analyze the irradiation damage, hardness, and structural changes in the near-surface area of samples. Prism coupling and end-face coupling methods were used to study the changes of optical waveguide properties under different annealing conditions. Considering the potential applications of low-loss waveguide structure in photoelectric sensors, electrical properties of (La, Sr)(Al, Ta)O 3 samples were studied as an important detection indicator of sensors.
{"title":"Damage, waveguide and electrical properties in (La, Sr)(Al, Ta)O3 single crystal irradiated with carbon ions","authors":"Mei Qiao, Tie-Jun Wang, Yong Liu, Tao Liu, Zhenxing Wang, Wanling Cui, Xiaoxin Wang, Xin Li, shicai xu","doi":"10.1364/josab.501291","DOIUrl":"https://doi.org/10.1364/josab.501291","url":null,"abstract":"The (La, Sr)(Al, Ta)O 3 crystal was irradiated via 20.0 MeV C ion with fluence of 1.0×10 15 ions/cm 2 . The Rutherford backscattering (RBS)/channeling spectra, the hardness and elastic modulus as continuous functions of the depth, and X-ray diffraction (XRD) are used to analyze the irradiation damage, hardness, and structural changes in the near-surface area of samples. Prism coupling and end-face coupling methods were used to study the changes of optical waveguide properties under different annealing conditions. Considering the potential applications of low-loss waveguide structure in photoelectric sensors, electrical properties of (La, Sr)(Al, Ta)O 3 samples were studied as an important detection indicator of sensors.","PeriodicalId":17280,"journal":{"name":"Journal of The Optical Society of America B-optical Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135132326","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}
Due to dependence of nanostructural material properties on the deposition conditions, the refractive index (RI) of a thin-metal alloy can vary by over 100×. For a more accurate RI estimation of thin-film alloys under a specific deposition condition, a model of RI for untested alloys is derived by extension from the alloy’s main element properties. One of the key derivations is to simplify RI polynomial equations into monomial expressions through four assumptions. Thus, a ratio method can accurately predict the RI of thin-film alloys from the properties of their main metals under the same deposition condition. The model is valid in the red to infrared spectrum for thin-film alloys MX where M is one of copper, silver, or gold and X is one or more elements with total concentration <10%.
{"title":"Predicting Refractive Index of Thin-Film Alloys by Extension from the Main Metal","authors":"Guowen Ding, Tevin Ding, Daniel Lin","doi":"10.1364/josab.497825","DOIUrl":"https://doi.org/10.1364/josab.497825","url":null,"abstract":"Due to dependence of nanostructural material properties on the deposition conditions, the refractive index (RI) of a thin-metal alloy can vary by over 100×. For a more accurate RI estimation of thin-film alloys under a specific deposition condition, a model of RI for untested alloys is derived by extension from the alloy’s main element properties. One of the key derivations is to simplify RI polynomial equations into monomial expressions through four assumptions. Thus, a ratio method can accurately predict the RI of thin-film alloys from the properties of their main metals under the same deposition condition. The model is valid in the red to infrared spectrum for thin-film alloys MX where M is one of copper, silver, or gold and X is one or more elements with total concentration <10%.","PeriodicalId":17280,"journal":{"name":"Journal of The Optical Society of America B-optical Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135132340","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}
Ming Zhang, Junyao Zhang, Ming Cui, Peng Dong, Baozhu Wang, Lin Yang, Xiuqing Zhang
In this study, we combined MATLAB with the rigorous electromagnetic field simulation software Computer Simulation Technology to perform a co-simulation method for inverse design of high-efficiency and broadband THz metasurface devices. In the proposed design method, genetic algorithm (GA) is embedded to realize automatic and inverse design. Aiming toward the different requirements of high-efficiency and broadband THz metasurface devices, different objective functions are set to optimize the design of different types of THz metasurface devices. Based on the rigorous electromagnetic simulation and genetic algorithm, the proposed design method can realize automatic and inverse design with high reliability, compared to the theoretical model based on catenary e-field theory. This study provides an important guiding role and an efficient method for designing and optimizing required metasurface devices with practical applied value.
{"title":"Accurate inverse design for high-efficiency and broadband terahertz devices by co-simulation with genetic algorithms","authors":"Ming Zhang, Junyao Zhang, Ming Cui, Peng Dong, Baozhu Wang, Lin Yang, Xiuqing Zhang","doi":"10.1364/josab.496383","DOIUrl":"https://doi.org/10.1364/josab.496383","url":null,"abstract":"In this study, we combined MATLAB with the rigorous electromagnetic field simulation software Computer Simulation Technology to perform a co-simulation method for inverse design of high-efficiency and broadband THz metasurface devices. In the proposed design method, genetic algorithm (GA) is embedded to realize automatic and inverse design. Aiming toward the different requirements of high-efficiency and broadband THz metasurface devices, different objective functions are set to optimize the design of different types of THz metasurface devices. Based on the rigorous electromagnetic simulation and genetic algorithm, the proposed design method can realize automatic and inverse design with high reliability, compared to the theoretical model based on catenary e-field theory. This study provides an important guiding role and an efficient method for designing and optimizing required metasurface devices with practical applied value.","PeriodicalId":17280,"journal":{"name":"Journal of The Optical Society of America B-optical Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135477769","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}
Dominic Hunter, Marcin Mrozowski, Allan McWilliam, Stuart Ingleby, Terry Dyer, Paul Griffin, Erling Riis
Spin preparation prior to a free-induction-decay (FID) measurement can be adversely affected by transverse bias fields, particularly in the geophysical field range. A strategy that enhances the spin polarization accumulated before readout is demonstrated, by synchronizing optical pumping with a magnetic field pulse that supersedes any transverse fields by over two orders of magnitude. The pulsed magnetic field is generated along the optical pumping axis using a compact electromagnetic coil pair encompassing a micro-electromechanical systems (MEMS) vapor cell. The coils also resistively heat the cesium vapor to the optimal atomic density without spurious magnetic field contributions as they are rapidly demagnetized to approximately zero field during spin readout. The demagnetization process is analyzed electronically, and directly with a FID measurement, to confirm that the residual magnetic field is minimal during detection. The sensitivity performance of this technique is compared to existing optical pumping modalities across a wide magnetic field range. A noise floor sensitivity of 238fT/Hz was achieved in a field of approximately 50 µT, in close agreement with the Cramér–Rao lower bound predicted noise density of 258fT/Hz.
自由电感衰减(FID)测量前的自旋制备会受到横向偏置场的不利影响，特别是在地球物理场范围内。一种策略，提高自旋极化积累前读出演示，通过同步光泵浦与磁场脉冲，取代任何横向场超过两个数量级。脉冲磁场沿光泵浦轴产生，使用紧凑的电磁线圈对包围微机电系统(MEMS)蒸气池。线圈也电阻加热铯蒸气到最佳的原子密度，没有虚假的磁场贡献，因为它们在自旋读出期间迅速退磁到大约为零的场。消磁过程通过电子方式进行分析，并直接使用FID测量，以确认在检测过程中残余磁场最小。将该技术的灵敏度性能与现有的光泵浦方式在宽磁场范围内进行了比较。在大约50µT的场域中，噪声底灵敏度达到238fT/Hz，与cram r - rao下限预测的258fT/Hz噪声密度密切一致。
{"title":"Free-induction-decay magnetometer with enhanced optical pumping","authors":"Dominic Hunter, Marcin Mrozowski, Allan McWilliam, Stuart Ingleby, Terry Dyer, Paul Griffin, Erling Riis","doi":"10.1364/josab.501086","DOIUrl":"https://doi.org/10.1364/josab.501086","url":null,"abstract":"Spin preparation prior to a free-induction-decay (FID) measurement can be adversely affected by transverse bias fields, particularly in the geophysical field range. A strategy that enhances the spin polarization accumulated before readout is demonstrated, by synchronizing optical pumping with a magnetic field pulse that supersedes any transverse fields by over two orders of magnitude. The pulsed magnetic field is generated along the optical pumping axis using a compact electromagnetic coil pair encompassing a micro-electromechanical systems (MEMS) vapor cell. The coils also resistively heat the cesium vapor to the optimal atomic density without spurious magnetic field contributions as they are rapidly demagnetized to approximately zero field during spin readout. The demagnetization process is analyzed electronically, and directly with a FID measurement, to confirm that the residual magnetic field is minimal during detection. The sensitivity performance of this technique is compared to existing optical pumping modalities across a wide magnetic field range. A noise floor sensitivity of 238fT/Hz was achieved in a field of approximately 50 µT, in close agreement with the Cramér–Rao lower bound predicted noise density of 258fT/Hz.","PeriodicalId":17280,"journal":{"name":"Journal of The Optical Society of America B-optical Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135477027","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}
Butterfly-shaped and dromion-like optical waves in a tapered graded-index waveguide (GRIN) with an external source are reported for the first time, to our knowledge. More pertinently, we obtain these waves both analytically and numerically in a generalized nonlinear Schrödinger equation (GNLSE), which describes self-similar wave propagation in GRIN with variable group-velocity dispersion (GVD), nonlinearity, gain, and source. The proposed GNLSE appertains to the study of similariton propagation through asymmetric twin-core fiber amplifiers. Dromion-like structures, which have generally been investigated in the (2+1) or higher dimensional systems, are reported in the (1+1) dimensional GNLSE with an external source. Herein, we introduce the concept of soliton management when the variable group-velocity dispersion and Kerr nonlinearity functions are suggested. For example, when the GVD parameter is perturbed, we observe the emergence of vibration of dromion-like structures. Then the dromion-like structure is transformed into oscillation by the modulation instability of the modified coefficient of the Gaussian GVD function, exhibiting interference based on two dromion-like structures. Additionally, the phenomenon of unbreakable P T symmetry of these nonlinear waves has been demonstrated for three explicit examples.
{"title":"Butterfly-shaped and dromion-like optical similaritons in asymmetric twin-core fiber amplifier","authors":"Soloman Thokala, Ashwin Myakalwar","doi":"10.1364/josab.501345","DOIUrl":"https://doi.org/10.1364/josab.501345","url":null,"abstract":"Butterfly-shaped and dromion-like optical waves in a tapered graded-index waveguide (GRIN) with an external source are reported for the first time, to our knowledge. More pertinently, we obtain these waves both analytically and numerically in a generalized nonlinear Schrödinger equation (GNLSE), which describes self-similar wave propagation in GRIN with variable group-velocity dispersion (GVD), nonlinearity, gain, and source. The proposed GNLSE appertains to the study of similariton propagation through asymmetric twin-core fiber amplifiers. Dromion-like structures, which have generally been investigated in the (2+1) or higher dimensional systems, are reported in the (1+1) dimensional GNLSE with an external source. Herein, we introduce the concept of soliton management when the variable group-velocity dispersion and Kerr nonlinearity functions are suggested. For example, when the GVD parameter is perturbed, we observe the emergence of vibration of dromion-like structures. Then the dromion-like structure is transformed into oscillation by the modulation instability of the modified coefficient of the Gaussian GVD function, exhibiting interference based on two dromion-like structures. Additionally, the phenomenon of unbreakable P T symmetry of these nonlinear waves has been demonstrated for three explicit examples.","PeriodicalId":17280,"journal":{"name":"Journal of The Optical Society of America B-optical Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135477759","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}
{"title":"A Review of Diffractive Deep Neural Networks","authors":"Yichen Sun, mingli dong, Mingxin Yu, xiaolin liu, Lianqing Zhu","doi":"10.1364/josab.497148","DOIUrl":"https://doi.org/10.1364/josab.497148","url":null,"abstract":"","PeriodicalId":17280,"journal":{"name":"Journal of The Optical Society of America B-optical Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135535377","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}
Songlin Jiang, Fei Fan, Yun-Yun Ji, Huijun Zhao, Jie -Rong Cheng, Xianghui Wang, Shengjiang Chang
The ultrawide tunable terahertz (THz) phase shifter has always been in high demand by THz applications, especially in terms of broadband transmission and phase modulation. In this paper, we design and fabricate a composite device that combines a double-layer liquid crystal (LC) with a double-sided etched grating metasurface. By introducing the natural anisotropy of LC based on the artificial anisotropy of the metasurface, the anisotropy of the device is significantly enhanced, and this anisotropy can be dynamically modulated by an external field. When the LC molecules rotate in the x − y plane, the experimental results show that the phase difference can vary between −83 ∘ and 277° at 0.52 THz with a large phase-shift modulation depth of 360° (i.e., 2 π ). The same phase-shift modulation depth can be obtained when the LC molecules rotate in the x − z plane, in which the phase difference can vary between 207° and 567° at 1.14 THz. Our proposed composite device shows an ultrawide phase shift regulation and an ultra-large phase-shift modulation depth in the THz regime, which may provide a new strategy for various THz phase and polarization devices.
{"title":"Ultrawide tunable terahertz phase shifter based on double-layer liquid crystal-dielectric grating","authors":"Songlin Jiang, Fei Fan, Yun-Yun Ji, Huijun Zhao, Jie -Rong Cheng, Xianghui Wang, Shengjiang Chang","doi":"10.1364/josab.497577","DOIUrl":"https://doi.org/10.1364/josab.497577","url":null,"abstract":"The ultrawide tunable terahertz (THz) phase shifter has always been in high demand by THz applications, especially in terms of broadband transmission and phase modulation. In this paper, we design and fabricate a composite device that combines a double-layer liquid crystal (LC) with a double-sided etched grating metasurface. By introducing the natural anisotropy of LC based on the artificial anisotropy of the metasurface, the anisotropy of the device is significantly enhanced, and this anisotropy can be dynamically modulated by an external field. When the LC molecules rotate in the x − y plane, the experimental results show that the phase difference can vary between −83 ∘ and 277° at 0.52 THz with a large phase-shift modulation depth of 360° (i.e., 2 π ). The same phase-shift modulation depth can be obtained when the LC molecules rotate in the x − z plane, in which the phase difference can vary between 207° and 567° at 1.14 THz. Our proposed composite device shows an ultrawide phase shift regulation and an ultra-large phase-shift modulation depth in the THz regime, which may provide a new strategy for various THz phase and polarization devices.","PeriodicalId":17280,"journal":{"name":"Journal of The Optical Society of America B-optical Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135769281","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：