Luyao Liu, Shuxian Wu, Ting Wu, Feihong Bao, Feifei Wang, Xiangyong Zhao, Qiaozhen Zhang, Jie Zou
This Letter presents a comparative study of surface acoustic wave (SAW) resonators on two different piezo-on-insulator (POI) substrates, 30° YX-LiNbO3/SiO2/sapphire and 30° YX-LiNbO3/SiO2/poly-Si/Si. The dispersion relationships between the resonant frequencies and wavelengths for the resonators, including the shear horizontal (SH) and Rayleigh modes, are investigated. The theoretical and experimental results showed that the main SH mode provides a larger coupling coefficient (K2) and that the spurious Rayleigh mode can be shifted from the passband and away from the main SH mode. Although the proposed POI SAW resonators on two different substrates have comparable frequencies for the same wavelength, the sapphire-based substrate exhibits a larger K2 of 28% and a higher fitted Bode-Qmax of 977 at 1.4 GHz. The temperature behavior of the SAW resonators is measured over a temperature range from −25 to 250 °C. The findings indicated that the resonator with the Si-based substrate has better temperature stability, with a temperature coefficient of frequency (TCF) of −16.99 ppm/°C and a turning point at 150 °C. In contrast, the one with the sapphire-based substrate provides a moderate TCF of −22.15 ppm/°C and remains linear for temperatures above 200 °C. This study reveals the impact of different substrate structures on the performance of SAW resonators, providing guidance for the design of desired SAW devices and their applications.
{"title":"Comparative study of lithium niobate thin films-based surface acoustic wave resonators including temperature characterization","authors":"Luyao Liu, Shuxian Wu, Ting Wu, Feihong Bao, Feifei Wang, Xiangyong Zhao, Qiaozhen Zhang, Jie Zou","doi":"10.1063/5.0244876","DOIUrl":"https://doi.org/10.1063/5.0244876","url":null,"abstract":"This Letter presents a comparative study of surface acoustic wave (SAW) resonators on two different piezo-on-insulator (POI) substrates, 30° YX-LiNbO3/SiO2/sapphire and 30° YX-LiNbO3/SiO2/poly-Si/Si. The dispersion relationships between the resonant frequencies and wavelengths for the resonators, including the shear horizontal (SH) and Rayleigh modes, are investigated. The theoretical and experimental results showed that the main SH mode provides a larger coupling coefficient (K2) and that the spurious Rayleigh mode can be shifted from the passband and away from the main SH mode. Although the proposed POI SAW resonators on two different substrates have comparable frequencies for the same wavelength, the sapphire-based substrate exhibits a larger K2 of 28% and a higher fitted Bode-Qmax of 977 at 1.4 GHz. The temperature behavior of the SAW resonators is measured over a temperature range from −25 to 250 °C. The findings indicated that the resonator with the Si-based substrate has better temperature stability, with a temperature coefficient of frequency (TCF) of −16.99 ppm/°C and a turning point at 150 °C. In contrast, the one with the sapphire-based substrate provides a moderate TCF of −22.15 ppm/°C and remains linear for temperatures above 200 °C. This study reveals the impact of different substrate structures on the performance of SAW resonators, providing guidance for the design of desired SAW devices and their applications.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"57 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143640058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
The plasmonic−nanofluidic system incorporates the nanoplasmonic metal structure with nanofluidic channel, exhibiting improved performance in optofluidic sensing. However, the device requires sophisticated nanofabrication, which is the main bottleneck for the practical applications. Here, we proposed a self-aligned plasmonic-nanofluidic device, in which both nanochannel and plasmonic nanostructures are readily fabricated and self-aligned by using only one step of direct laser writing. Specifically, we use a single gold subwavelength nanochannel to simultaneously apply both spatial confinement and plasmonic enhancement. Furthermore, instead of using an ultrafast laser, we demonstrate the feasibility of drilling nanochannels on suspended substrate using continuous lasers. In contrast to conventional plasmonic nanochannels with plasmonic enhancement only under transverse magnetic (TM) mode laser, our sample presents obvious plasmonic effects under both TM and transverse electric mode lasers, which is beneficial for improving the overall signal. Our method has great potential in the widespread adoption of the plasmonic-nanofluidic system.
{"title":"Self-aligned plasmonic-nanofluidic system by continuous laser manufacturing","authors":"Yizhen Yu, Bo Yang, HuiJuan Huang, Rui Wang","doi":"10.1063/5.0255321","DOIUrl":"https://doi.org/10.1063/5.0255321","url":null,"abstract":"The plasmonic−nanofluidic system incorporates the nanoplasmonic metal structure with nanofluidic channel, exhibiting improved performance in optofluidic sensing. However, the device requires sophisticated nanofabrication, which is the main bottleneck for the practical applications. Here, we proposed a self-aligned plasmonic-nanofluidic device, in which both nanochannel and plasmonic nanostructures are readily fabricated and self-aligned by using only one step of direct laser writing. Specifically, we use a single gold subwavelength nanochannel to simultaneously apply both spatial confinement and plasmonic enhancement. Furthermore, instead of using an ultrafast laser, we demonstrate the feasibility of drilling nanochannels on suspended substrate using continuous lasers. In contrast to conventional plasmonic nanochannels with plasmonic enhancement only under transverse magnetic (TM) mode laser, our sample presents obvious plasmonic effects under both TM and transverse electric mode lasers, which is beneficial for improving the overall signal. Our method has great potential in the widespread adoption of the plasmonic-nanofluidic system.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"33 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143640473","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Rachit Dobhal, Yuan-Ming Liu, Jih-Chao Chiu, Hsien-Ming Sung, Yu-Shan Wu, Yu-Cheng Fan, Johannes Gracia, Rong-Wei Ma, Hidenari Fujiwara, C. W. Liu
Counterclockwise (CCW) hysteresis with a memory window (MW) of 2.4 V is observed in amorphous indium oxide (a-In2O3) thin-film transistors with silicon oxide (SiOX) gate insulator (40 nm). This CCW phenomenon is due to the dipole formation between the a-In2O3 channel and the SiOX gate insulator by relocating oxygen atoms under the influence of the applied electric field. Hence, bipolar switching of gate bias (VGS) alters the dipole direction and leads to low (VTL) and high (VTH) threshold voltages. The dipole formation increases with the electric field, which can be tailored by gate oxide (SiOX) thickness or gate bias (VGS). Therefore, the devices with a gate oxide thickness of 200 nm initially showed the clockwise hysteresis at VGS of 2 V, transformed to the CCW (MW of 4.2 V) with an increase in gate bias to 14 V. Therefore, a difference in oxygen density at the interface can form a dipole to exhibit the CCW phenomenon and behave FeFET-like.
{"title":"Amorphous In2O3 FeFET-like devices by interface dipoles","authors":"Rachit Dobhal, Yuan-Ming Liu, Jih-Chao Chiu, Hsien-Ming Sung, Yu-Shan Wu, Yu-Cheng Fan, Johannes Gracia, Rong-Wei Ma, Hidenari Fujiwara, C. W. Liu","doi":"10.1063/5.0255212","DOIUrl":"https://doi.org/10.1063/5.0255212","url":null,"abstract":"Counterclockwise (CCW) hysteresis with a memory window (MW) of 2.4 V is observed in amorphous indium oxide (a-In2O3) thin-film transistors with silicon oxide (SiOX) gate insulator (40 nm). This CCW phenomenon is due to the dipole formation between the a-In2O3 channel and the SiOX gate insulator by relocating oxygen atoms under the influence of the applied electric field. Hence, bipolar switching of gate bias (VGS) alters the dipole direction and leads to low (VTL) and high (VTH) threshold voltages. The dipole formation increases with the electric field, which can be tailored by gate oxide (SiOX) thickness or gate bias (VGS). Therefore, the devices with a gate oxide thickness of 200 nm initially showed the clockwise hysteresis at VGS of 2 V, transformed to the CCW (MW of 4.2 V) with an increase in gate bias to 14 V. Therefore, a difference in oxygen density at the interface can form a dipole to exhibit the CCW phenomenon and behave FeFET-like.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"25 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143640479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
J. Cañas, A. Grenier, J. L. Rouviere, A. Harikumar, S. Ndiaye, A. Jannaud, E. Monroy, L. Rigutti
We demonstrate the application of atom probe tomography for assessing the crystalline orientation of nanoscale semiconductor structures via the analysis of charge state ratio maps in the detector space. The experimental realization is carried out in the context of adventitious cone-shaped domains present in AlGaN quantum dot superlattices. The cone-shaped domains, which emerge from shallow pits generated in AlN and propagate through the superlattices, are shown to exhibit small misorientation angles of their crystalline 〈0001〉 poles. The results of the atom probe tomography analysis are confirmed by convergent beam electron diffraction measurements. The use of this methodology adds another layer to the application of this technique to semiconductor nanoscale systems, providing not only compositional maps but also information on the crystallographic orientation.
{"title":"Assessment of the crystalline orientation of nanoscale semiconductor structures via atom probe tomography","authors":"J. Cañas, A. Grenier, J. L. Rouviere, A. Harikumar, S. Ndiaye, A. Jannaud, E. Monroy, L. Rigutti","doi":"10.1063/5.0242659","DOIUrl":"https://doi.org/10.1063/5.0242659","url":null,"abstract":"We demonstrate the application of atom probe tomography for assessing the crystalline orientation of nanoscale semiconductor structures via the analysis of charge state ratio maps in the detector space. The experimental realization is carried out in the context of adventitious cone-shaped domains present in AlGaN quantum dot superlattices. The cone-shaped domains, which emerge from shallow pits generated in AlN and propagate through the superlattices, are shown to exhibit small misorientation angles of their crystalline 〈0001〉 poles. The results of the atom probe tomography analysis are confirmed by convergent beam electron diffraction measurements. The use of this methodology adds another layer to the application of this technique to semiconductor nanoscale systems, providing not only compositional maps but also information on the crystallographic orientation.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"17 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143640050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Yuyang Ye, Xin Hu, Yiwei Li, Yuming Guo, Fangzhou Chen, Ning Li, Xiubao Sui
We introduce a heterostructure integrating a two-dimensional nonlinear GaSe film on a silicon metasurface supporting quasi-bound states in the continuum (BIC) mode, to enhance the nonlinear sum-frequency generation (SFG) process in the GaSe film, where incoming shortwave infrared (SWIR) photons are upconverted to visible photons. The wavelength selectivity in the silicon metasurface corresponding to different configurations enables the GaSe film/silicon tunable metasurface heterostructure to have a response in the range of 1500–1630 nm, covering the telecommunication C and L bands. The response spectrum is derived from the dual quasi-bound states in the continuum resonance of the metasurface structure, and the pump light and signal light correspond to the dual quasi-bound states in the continuum resonances of the metasurface structure. The high quality-factor of the quasi-bound states in the continuum resonance brought by the metasurface greatly improves the density of the electromagnetic field near the GaSe film, thus improving the sum-frequency generation conversion efficiency in the GaSe film. The pump and signal corresponding to the dual quasi-bound states in the continuum resonances introduced by the silicon metasurface are designed in the telecommunication band, while the sum-frequency light is located in the range that can be directly detected by a silicon detector. The low noise level in a silicon detector can guarantee the high sensitivity detection of shortwave infrared light. The results indicate that the upconversion detector attained a peak detectivity of 1.4 × 1012 Jones at 1555.1 nm, comparable to commercial broadband InGaAs detectors (Thorlabs).
{"title":"Infrared upconversion detection based on two-dimensional material/silicon tunable metasurface heterostructures for telecommunication","authors":"Yuyang Ye, Xin Hu, Yiwei Li, Yuming Guo, Fangzhou Chen, Ning Li, Xiubao Sui","doi":"10.1063/5.0251356","DOIUrl":"https://doi.org/10.1063/5.0251356","url":null,"abstract":"We introduce a heterostructure integrating a two-dimensional nonlinear GaSe film on a silicon metasurface supporting quasi-bound states in the continuum (BIC) mode, to enhance the nonlinear sum-frequency generation (SFG) process in the GaSe film, where incoming shortwave infrared (SWIR) photons are upconverted to visible photons. The wavelength selectivity in the silicon metasurface corresponding to different configurations enables the GaSe film/silicon tunable metasurface heterostructure to have a response in the range of 1500–1630 nm, covering the telecommunication C and L bands. The response spectrum is derived from the dual quasi-bound states in the continuum resonance of the metasurface structure, and the pump light and signal light correspond to the dual quasi-bound states in the continuum resonances of the metasurface structure. The high quality-factor of the quasi-bound states in the continuum resonance brought by the metasurface greatly improves the density of the electromagnetic field near the GaSe film, thus improving the sum-frequency generation conversion efficiency in the GaSe film. The pump and signal corresponding to the dual quasi-bound states in the continuum resonances introduced by the silicon metasurface are designed in the telecommunication band, while the sum-frequency light is located in the range that can be directly detected by a silicon detector. The low noise level in a silicon detector can guarantee the high sensitivity detection of shortwave infrared light. The results indicate that the upconversion detector attained a peak detectivity of 1.4 × 1012 Jones at 1555.1 nm, comparable to commercial broadband InGaAs detectors (Thorlabs).","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"27 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143640053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Asymmetric transmission (AT) materials allow light to pass through differently depending on its direction, which is important for optical devices like isolators, encryption, and solar cells. Here, we propose and experimentally demonstrate an approach to achieve AT at optical frequencies by using three-dimensional gradient spiral photonic crystals (PCs). By analyzing the iso frequency surface's response of spiral photonic crystals, we predict the AT of light at certain incident angles. We fabricate dielectric spiral PCs with different gradients of 1%, 11%, and 28% in the z-direction using the femtosecond laser direct writing technique. The predicted AT of light and the dependence of AT on the structural gradient amplitude due to the complex dispersion relations in PCs have been revealed through experimental measurements. These results demonstrate the potential of gradient 3D PCs in the development of diverse (AT) optical devices.
{"title":"Angle-dependent asymmetric transmission in gradient 3D photonic crystals","authors":"Xian-zi Dong, Yong-liang Zhang, Feng Jin, Yuan-yuan Zhao, Xuan-ming Duan, Mei-ling Zheng","doi":"10.1063/5.0251657","DOIUrl":"https://doi.org/10.1063/5.0251657","url":null,"abstract":"Asymmetric transmission (AT) materials allow light to pass through differently depending on its direction, which is important for optical devices like isolators, encryption, and solar cells. Here, we propose and experimentally demonstrate an approach to achieve AT at optical frequencies by using three-dimensional gradient spiral photonic crystals (PCs). By analyzing the iso frequency surface's response of spiral photonic crystals, we predict the AT of light at certain incident angles. We fabricate dielectric spiral PCs with different gradients of 1%, 11%, and 28% in the z-direction using the femtosecond laser direct writing technique. The predicted AT of light and the dependence of AT on the structural gradient amplitude due to the complex dispersion relations in PCs have been revealed through experimental measurements. These results demonstrate the potential of gradient 3D PCs in the development of diverse (AT) optical devices.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"818 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143640055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
GeSe, an emerging two-dimensional material, exhibits a significant potential in nonlinear optics. This study explores an effective method to enhance the nonlinear optical properties of GeSe through the utilization of a multilayer film structure. We designed and fabricated a (SiO2/ZnSe/GeSe/ZnSe)4/SiO2 multilayer film structure, which substantially augments the nonlinear optical response of GeSe via electric field enhancement and transmission spectrum edge modulation. Z-scan measurements reveal that the two-photon absorption coefficient and nonlinear refractive index of the multilayer film reach 25.616×104 cm/GW and 8.235×10−13 m2/W, representing more than a fourfold increase compared to a single GeSe film. A further analysis of optical limiting characteristics reveals onset and optical limiting thresholds of 0.043 and 0.711 GW/cm2, respectively. This multilayer film design strategy significantly enhances the nonlinear optical performance of GeSe, offering possibilities for developing high-efficiency optical modulators and optical switches based on two-dimensional materials.
{"title":"Enhanced nonlinear optical response in GeSe-based multilayer structure","authors":"Chunzheng Bai, Wenbin Xiang, Jin Chen, Baohua Zhu, Qihao Sun, Changgui Lv, Bing Gu, Boping Yang, Jiayu Zhang","doi":"10.1063/5.0248054","DOIUrl":"https://doi.org/10.1063/5.0248054","url":null,"abstract":"GeSe, an emerging two-dimensional material, exhibits a significant potential in nonlinear optics. This study explores an effective method to enhance the nonlinear optical properties of GeSe through the utilization of a multilayer film structure. We designed and fabricated a (SiO2/ZnSe/GeSe/ZnSe)4/SiO2 multilayer film structure, which substantially augments the nonlinear optical response of GeSe via electric field enhancement and transmission spectrum edge modulation. Z-scan measurements reveal that the two-photon absorption coefficient and nonlinear refractive index of the multilayer film reach 25.616×104 cm/GW and 8.235×10−13 m2/W, representing more than a fourfold increase compared to a single GeSe film. A further analysis of optical limiting characteristics reveals onset and optical limiting thresholds of 0.043 and 0.711 GW/cm2, respectively. This multilayer film design strategy significantly enhances the nonlinear optical performance of GeSe, offering possibilities for developing high-efficiency optical modulators and optical switches based on two-dimensional materials.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"55 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143640462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Liquid marble (LM) is a droplet covered with jammed low-wettability fine particles, which exhibits non-sticking to contacting media while keeping its fluid reconfigurability. While the LM facilitated the handling of the droplet, LM breaks down upon squeezing, which limits the robust handling. Here, we show that LM exhibits high compression stability when the jammed particles distort the liquid surface to form sub- to single-micron roughness. We find that the particle layers' distortion increases with the evaporation of the inner liquid. Thus, we regulated the evaporation degree of the droplet by varying the mixing ratio of the nonvolatile and volatile liquids. First, we show the regulation of the mixing ratio and its effect on the equilibrium LM static shape and particle layer structure. Then, the effect of the LMs' surface structure on their mechanical response is explored. When 90% of the inner liquid is evaporated, the submicrometer wrinkle structure appears on the LM surface. We name the LM with the wrinkle structure “wrinkled liquid marble (WLM).” The WLM exhibited high compression stability and significantly higher resilience force than the droplet one. We believe this work helps the practical use of the LMs by improving their mechanical stability. Moreover, the fundamental understanding of the particle layer stability at the interface can be advanced.
{"title":"Mechanically robust wrinkled liquid marbles","authors":"Mizuki Tenjimbayashi","doi":"10.1063/5.0256903","DOIUrl":"https://doi.org/10.1063/5.0256903","url":null,"abstract":"Liquid marble (LM) is a droplet covered with jammed low-wettability fine particles, which exhibits non-sticking to contacting media while keeping its fluid reconfigurability. While the LM facilitated the handling of the droplet, LM breaks down upon squeezing, which limits the robust handling. Here, we show that LM exhibits high compression stability when the jammed particles distort the liquid surface to form sub- to single-micron roughness. We find that the particle layers' distortion increases with the evaporation of the inner liquid. Thus, we regulated the evaporation degree of the droplet by varying the mixing ratio of the nonvolatile and volatile liquids. First, we show the regulation of the mixing ratio and its effect on the equilibrium LM static shape and particle layer structure. Then, the effect of the LMs' surface structure on their mechanical response is explored. When 90% of the inner liquid is evaporated, the submicrometer wrinkle structure appears on the LM surface. We name the LM with the wrinkle structure “wrinkled liquid marble (WLM).” The WLM exhibited high compression stability and significantly higher resilience force than the droplet one. We believe this work helps the practical use of the LMs by improving their mechanical stability. Moreover, the fundamental understanding of the particle layer stability at the interface can be advanced.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"14 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143640471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
The metalenses have been extensively studied for their compact and flexible characteristics in focusing and imaging applications. However, it remains a significant challenge to design a broadband achromatic metalens that maintains high efficiency under arbitrary polarization incidence. In this work, we design a broadband achromatic metalens that achieves polarization-insensitive, high-efficiency focusing by effectively utilizing both co-polarization and cross-polarization terms of the transmitted light. Using a minimalist anisotropic nanofin library, we optimize the phase distribution of the metalens at each designed wavelength with the particle swarm algorithm. Numerical simulations demonstrate a stable focal length with a deviation of less than 4% and an average focusing efficiency of 80.5% in the visible wavelength range of 450–650 nm. Moreover, we design a multi-wavelength off-axis bi-focal metalens to demonstrate the flexible control of output light phase and dispersion achieved by this method. The generality of this design enables its implementation in various metasurface devices, accelerating applications in high-quality and multi-channel image display.
{"title":"High-efficiency broadband achromatic metalens in the visible","authors":"Liang Hou, Hongyuan Zhou, Dandan Zhang, Ganqing Lu, Dejian Zhang, Tingting Liu, Shuyuan Xiao, Tianbao Yu","doi":"10.1063/5.0240728","DOIUrl":"https://doi.org/10.1063/5.0240728","url":null,"abstract":"The metalenses have been extensively studied for their compact and flexible characteristics in focusing and imaging applications. However, it remains a significant challenge to design a broadband achromatic metalens that maintains high efficiency under arbitrary polarization incidence. In this work, we design a broadband achromatic metalens that achieves polarization-insensitive, high-efficiency focusing by effectively utilizing both co-polarization and cross-polarization terms of the transmitted light. Using a minimalist anisotropic nanofin library, we optimize the phase distribution of the metalens at each designed wavelength with the particle swarm algorithm. Numerical simulations demonstrate a stable focal length with a deviation of less than 4% and an average focusing efficiency of 80.5% in the visible wavelength range of 450–650 nm. Moreover, we design a multi-wavelength off-axis bi-focal metalens to demonstrate the flexible control of output light phase and dispersion achieved by this method. The generality of this design enables its implementation in various metasurface devices, accelerating applications in high-quality and multi-channel image display.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"39 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143631171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Yangjun Qin, Zhicheng Zong, Junwei Che, Tianhao Li, Haisheng Fang, Nuo Yang
The unique properties of plastic crystals highlight their potential for use in solid-state refrigeration. However, their practical applications are limited by thermal hysteresis due to low thermal conductivity. In this study, the effect of compressive strain on the thermal transport properties of [(CH3)4N][FeCl4] was investigated using molecular dynamic simulation with a deep potential. It is found that the thermal conductivities along the [100], [010], [001], [101], and [011] directions are enhanced under 9% strain by 110%, 580%, 114%, 408%, and 268%, respectively. The underlying mechanisms are analyzed through vibrational density of states and spectral energy densities. The enhancement in thermal conductivity is primarily due to reduced phonon scattering. These findings offer theoretical insights for the practical application of plastic crystals in thermal management systems.
{"title":"A significant enhancement in thermal conductivity of plastic crystals under compressive strain by deep potential molecular dynamics","authors":"Yangjun Qin, Zhicheng Zong, Junwei Che, Tianhao Li, Haisheng Fang, Nuo Yang","doi":"10.1063/5.0243420","DOIUrl":"https://doi.org/10.1063/5.0243420","url":null,"abstract":"The unique properties of plastic crystals highlight their potential for use in solid-state refrigeration. However, their practical applications are limited by thermal hysteresis due to low thermal conductivity. In this study, the effect of compressive strain on the thermal transport properties of [(CH3)4N][FeCl4] was investigated using molecular dynamic simulation with a deep potential. It is found that the thermal conductivities along the [100], [010], [001], [101], and [011] directions are enhanced under 9% strain by 110%, 580%, 114%, 408%, and 268%, respectively. The underlying mechanisms are analyzed through vibrational density of states and spectral energy densities. The enhancement in thermal conductivity is primarily due to reduced phonon scattering. These findings offer theoretical insights for the practical application of plastic crystals in thermal management systems.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"16 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143631179","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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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