Gallium (Ga) exhibits remarkable potential in flexible electronics, chemistry, and biomedicine due to its exceptional physical properties. The phase transition and supercooling characteristics of Ga have led to the emergence of numerous valuable applications. In this paper, we capitalize on this foundation by utilizing optofluidic microcavities supporting both high quality factor optical and optomechanical modes to investigate the phase transformation process and supercooling properties of Ga. Our study provides comprehensive insights into the dynamic behavior of Ga during the complete phase transition, such as measuring a hysteresis loop between the solid-to-liquid and liquid-to-solid transitions, revealing nonreciprocal resonance wavelength shift, and identifying a unique metastability state of Ga during melting. The linear thermal expansion coefficients of Ga were precisely measured to be 0.41 × 10−5 K−1 and −0.75 × 10−5 K−1 for solid and liquid Ga, respectively. Our research provides a comprehensive and versatile monitoring platform for newly fabricated liquid metal alloys, offering multidimensional insights into their phase transition behavior.
{"title":"Observation of the liquid metal phase transition in optofluidic microcavities","authors":"Zixiang Fu, Zhenlin Zhao, Ruiji Dong, Junqiang Guo, Yan-Lei Zhang, Shusen Xie, Xianzeng Zhang, Qijing Lu","doi":"10.1038/s44310-024-00022-9","DOIUrl":"10.1038/s44310-024-00022-9","url":null,"abstract":"Gallium (Ga) exhibits remarkable potential in flexible electronics, chemistry, and biomedicine due to its exceptional physical properties. The phase transition and supercooling characteristics of Ga have led to the emergence of numerous valuable applications. In this paper, we capitalize on this foundation by utilizing optofluidic microcavities supporting both high quality factor optical and optomechanical modes to investigate the phase transformation process and supercooling properties of Ga. Our study provides comprehensive insights into the dynamic behavior of Ga during the complete phase transition, such as measuring a hysteresis loop between the solid-to-liquid and liquid-to-solid transitions, revealing nonreciprocal resonance wavelength shift, and identifying a unique metastability state of Ga during melting. The linear thermal expansion coefficients of Ga were precisely measured to be 0.41 × 10−5 K−1 and −0.75 × 10−5 K−1 for solid and liquid Ga, respectively. Our research provides a comprehensive and versatile monitoring platform for newly fabricated liquid metal alloys, offering multidimensional insights into their phase transition behavior.","PeriodicalId":501711,"journal":{"name":"npj Nanophotonics","volume":" ","pages":"1-8"},"PeriodicalIF":0.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s44310-024-00022-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141500515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-02DOI: 10.1038/s44310-024-00021-w
Stephan Wong, Terry A. Loring, Alexander Cerjan
In the recent years, photonic Chern materials have attracted substantial interest as they feature topological edge states that are robust against disorder, promising to realize defect-agnostic integrated photonic crystal slab devices. However, the out-of-plane radiative losses in those photonic Chern slabs has been previously neglected, yielding limited accuracy for predictions of these systems’ topological protection. Here, we develop a general framework for measuring the topological protection in photonic systems, such as in photonic crystal slabs, while accounting for in-plane and out-of-plane radiative losses. Our approach relies on the spectral localizer that combines the position and Hamiltonian matrices of the system to draw a real-picture of the system’s topology. This operator-based approach to topology allows us to use an effective Hamiltonian directly derived from the full-wave Maxwell equations after discretization via finite-elements method (FEM), resulting in the full account of all the system’s physical processes. As the spectral FEM-localizer is constructed solely from FEM discretization of the system’s master equation, the proposed framework is applicable to any physical system and is compatible with commonly used FEM software. Moving forward, we anticipate the generality of the method to aid in the topological classification of a broad range of complex physical systems.
{"title":"Classifying topology in photonic crystal slabs with radiative environments","authors":"Stephan Wong, Terry A. Loring, Alexander Cerjan","doi":"10.1038/s44310-024-00021-w","DOIUrl":"10.1038/s44310-024-00021-w","url":null,"abstract":"In the recent years, photonic Chern materials have attracted substantial interest as they feature topological edge states that are robust against disorder, promising to realize defect-agnostic integrated photonic crystal slab devices. However, the out-of-plane radiative losses in those photonic Chern slabs has been previously neglected, yielding limited accuracy for predictions of these systems’ topological protection. Here, we develop a general framework for measuring the topological protection in photonic systems, such as in photonic crystal slabs, while accounting for in-plane and out-of-plane radiative losses. Our approach relies on the spectral localizer that combines the position and Hamiltonian matrices of the system to draw a real-picture of the system’s topology. This operator-based approach to topology allows us to use an effective Hamiltonian directly derived from the full-wave Maxwell equations after discretization via finite-elements method (FEM), resulting in the full account of all the system’s physical processes. As the spectral FEM-localizer is constructed solely from FEM discretization of the system’s master equation, the proposed framework is applicable to any physical system and is compatible with commonly used FEM software. Moving forward, we anticipate the generality of the method to aid in the topological classification of a broad range of complex physical systems.","PeriodicalId":501711,"journal":{"name":"npj Nanophotonics","volume":" ","pages":"1-9"},"PeriodicalIF":0.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s44310-024-00021-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141500526","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-02DOI: 10.1038/s44310-024-00026-5
Meng Huang, John Ballato, Anna C. Peacock
Semiconductor core, glass cladding fibres that can be produced with scalable dimensions and unique waveguide designs are offering new opportunities for nonlinear photonics. This paper reviews developments in the fabrication and post-processing of such semiconductor core fibres and their enabling of low loss and high efficiency nonlinear components across wavelengths spanning the near- to mid-infrared. Through adaption and expansion of the production processes, routes to new core materials are being opened that could extend the application space, whilst all-fibre integration methods will result in more robust and practical semiconductor systems. Through continued improvement in the core materials, fibre designs and transmission losses, semiconductor fibres are poised to bring unique functionality to both the fibre and semiconductor research fields and their practical application into a myriad of optoelectronic devices.
{"title":"Semiconductor core fibres: a scalable platform for nonlinear photonics","authors":"Meng Huang, John Ballato, Anna C. Peacock","doi":"10.1038/s44310-024-00026-5","DOIUrl":"10.1038/s44310-024-00026-5","url":null,"abstract":"Semiconductor core, glass cladding fibres that can be produced with scalable dimensions and unique waveguide designs are offering new opportunities for nonlinear photonics. This paper reviews developments in the fabrication and post-processing of such semiconductor core fibres and their enabling of low loss and high efficiency nonlinear components across wavelengths spanning the near- to mid-infrared. Through adaption and expansion of the production processes, routes to new core materials are being opened that could extend the application space, whilst all-fibre integration methods will result in more robust and practical semiconductor systems. Through continued improvement in the core materials, fibre designs and transmission losses, semiconductor fibres are poised to bring unique functionality to both the fibre and semiconductor research fields and their practical application into a myriad of optoelectronic devices.","PeriodicalId":501711,"journal":{"name":"npj Nanophotonics","volume":" ","pages":"1-12"},"PeriodicalIF":0.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s44310-024-00026-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141500487","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-01DOI: 10.1038/s44310-024-00016-7
Michele Cotrufo, Jonas H. Krakofsky, Sander A. Mann, Gerhard Boehm, Mikhail A. Belkin, Andrea Alù
Nonlinear intersubband polaritonic metasurfaces support one of the strongest known ultrafast nonlinear responses in the mid-infrared frequency range across all condensed matter systems. Beyond harmonic generation and frequency mixing, these nonlinearities can be leveraged for ultrafast optical switching and power limiting, based on tailored transitions from strong to weak polaritonic coupling. Here, we demonstrate synergistic optimization of materials and photonic nanostructures to achieve large reflection contrast in ultrafast polaritonic metasurface limiters. The devices are based on optimized semiconductor heterostructure materials that minimize the intersubband transition linewidth and reduce absorption in optically-saturated nanoresonators, achieving a record-high reflection contrast of 54% experimentally. We also discuss opportunities to further boost the metrics of performance of this class of ultrafast limiters, showing that reflection contrast as high as 94% may be realistically achieved using all-dielectric intersubband polaritonic metasurfaces.
{"title":"Intersubband polaritonic metasurfaces for high-contrast ultra-fast power limiting and optical switching","authors":"Michele Cotrufo, Jonas H. Krakofsky, Sander A. Mann, Gerhard Boehm, Mikhail A. Belkin, Andrea Alù","doi":"10.1038/s44310-024-00016-7","DOIUrl":"10.1038/s44310-024-00016-7","url":null,"abstract":"Nonlinear intersubband polaritonic metasurfaces support one of the strongest known ultrafast nonlinear responses in the mid-infrared frequency range across all condensed matter systems. Beyond harmonic generation and frequency mixing, these nonlinearities can be leveraged for ultrafast optical switching and power limiting, based on tailored transitions from strong to weak polaritonic coupling. Here, we demonstrate synergistic optimization of materials and photonic nanostructures to achieve large reflection contrast in ultrafast polaritonic metasurface limiters. The devices are based on optimized semiconductor heterostructure materials that minimize the intersubband transition linewidth and reduce absorption in optically-saturated nanoresonators, achieving a record-high reflection contrast of 54% experimentally. We also discuss opportunities to further boost the metrics of performance of this class of ultrafast limiters, showing that reflection contrast as high as 94% may be realistically achieved using all-dielectric intersubband polaritonic metasurfaces.","PeriodicalId":501711,"journal":{"name":"npj Nanophotonics","volume":" ","pages":"1-10"},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s44310-024-00016-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141489088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-28DOI: 10.1038/s44310-024-00015-8
Yang Chen, Xuejuan Wu, Linpeng Lu, Jiasong Sun, Runnan Zhang, Wenhui Lin, Yufan Chen, Maciej Trusiak, Peng Gao, Chao Zuo
Lens-free on-chip microscopy (LFOCM) has been widely utilized in digital pathology, drug screening, point-of-care testing (POCT), and quantitative phase imaging (QPI) due to its high throughput imaging capability and compactness. Initially, coherent laser sources were used in LFOCM to generate interference fringes to reconstruct the intensity and phase information of an object. The use of partially coherent light-emitting diodes (LEDs) in LFOCM offers a more portable and cost-effective alternative to conventional coherent illumination sources. However, the coherence-gating effect from a relatively low degree of coherence may cause a blur of high-frequency information in holograms, leading to an inaccurate object recovery. Thus, we present a pixel-super-resolved lens-free quantitative phase microscopy (PSR-LFQPM) with partially coherent illumination, which not only compensates for the impact of low coherence without increasing the volume of the system but also suppresses the theoretical Nyquist-Shannon sampling resolution limit imposed by the sensor pixel size (0.9 μm). Based on the partially coherent imaging model, we integrate the spatial coherence transfer function (SCTF) obtained from the pre-calibrated LED source distribution during the iteration process to obtain an accurate high-resolution recovery. Applying PSR-LFQPM to image living HeLa cells in vitro, we achieve real-time dynamic high-throughput QPI performance (half-pitch resolution of 780 nm with a 1.41-fold improvement compared to results without considering the effect of coherence) across a wide FOV (19.53 mm2). The proposed method provides a compact, low-cost, and high-throughput lens-free on-chip microscopy system for biomedical and POCT applications.
{"title":"Pixel-super-resolved lens-free quantitative phase microscopy with partially coherent illumination","authors":"Yang Chen, Xuejuan Wu, Linpeng Lu, Jiasong Sun, Runnan Zhang, Wenhui Lin, Yufan Chen, Maciej Trusiak, Peng Gao, Chao Zuo","doi":"10.1038/s44310-024-00015-8","DOIUrl":"10.1038/s44310-024-00015-8","url":null,"abstract":"Lens-free on-chip microscopy (LFOCM) has been widely utilized in digital pathology, drug screening, point-of-care testing (POCT), and quantitative phase imaging (QPI) due to its high throughput imaging capability and compactness. Initially, coherent laser sources were used in LFOCM to generate interference fringes to reconstruct the intensity and phase information of an object. The use of partially coherent light-emitting diodes (LEDs) in LFOCM offers a more portable and cost-effective alternative to conventional coherent illumination sources. However, the coherence-gating effect from a relatively low degree of coherence may cause a blur of high-frequency information in holograms, leading to an inaccurate object recovery. Thus, we present a pixel-super-resolved lens-free quantitative phase microscopy (PSR-LFQPM) with partially coherent illumination, which not only compensates for the impact of low coherence without increasing the volume of the system but also suppresses the theoretical Nyquist-Shannon sampling resolution limit imposed by the sensor pixel size (0.9 μm). Based on the partially coherent imaging model, we integrate the spatial coherence transfer function (SCTF) obtained from the pre-calibrated LED source distribution during the iteration process to obtain an accurate high-resolution recovery. Applying PSR-LFQPM to image living HeLa cells in vitro, we achieve real-time dynamic high-throughput QPI performance (half-pitch resolution of 780 nm with a 1.41-fold improvement compared to results without considering the effect of coherence) across a wide FOV (19.53 mm2). The proposed method provides a compact, low-cost, and high-throughput lens-free on-chip microscopy system for biomedical and POCT applications.","PeriodicalId":501711,"journal":{"name":"npj Nanophotonics","volume":" ","pages":"1-9"},"PeriodicalIF":0.0,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s44310-024-00015-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141489083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chirality describes mirror symmetry breaking in geometric structures or certain physical quantities. The interaction between chiral structure and chiral light provides a rich collection of means for studying the chirality of substances. Recently, optical chiral metasurfaces have emerged as planar or quasi-planar photonic devices composed of subwavelength chiral unit cells, offering distinct appealing optical responses to circularly polarized light with opposite handedness. The chiroptical effects in optical metasurfaces can be manifested in the absorption, scattering, and even emission spectra under the circular polarization bases. A broadband chiroptical effect is highly desired for many passive chiral applications such as pure circular polarizers, chiral imaging, and chiral holography, in which cases the resonances should be avoided. On the other hand, resonant chiroptical responses are particularly needed in many situations requiring strong chiral field enhancement such as chiral sensing and chiral emission. This article reviews the latest research on both broadband and resonant chiral metasurfaces. First, we discuss the basic principle of different types of chiroptical effects including 3D/2D optical chirality and intrinsic/extrinsic optical chirality. Then we review typical means for broadband chiral metasurfaces, and related chiral photonic devices including broadband circular polarizers, chiral imaging and chiral holography. Then, we discuss the interaction between chiral light and matter enhanced by resonant chiral metasurfaces, especially for the chiral bound states in the continuum metasurfaces with ultra-high quality factors, which are particularly important for chiral molecule sensing, and chiral light sources. In the final section, the review concludes with an outlook on future directions in chiral photonics.
{"title":"Advances on broadband and resonant chiral metasurfaces","authors":"Qian-Mei Deng, Xin Li, Meng-Xia Hu, Feng-Jun Li, Xiangping Li, Zi-Lan Deng","doi":"10.1038/s44310-024-00018-5","DOIUrl":"10.1038/s44310-024-00018-5","url":null,"abstract":"Chirality describes mirror symmetry breaking in geometric structures or certain physical quantities. The interaction between chiral structure and chiral light provides a rich collection of means for studying the chirality of substances. Recently, optical chiral metasurfaces have emerged as planar or quasi-planar photonic devices composed of subwavelength chiral unit cells, offering distinct appealing optical responses to circularly polarized light with opposite handedness. The chiroptical effects in optical metasurfaces can be manifested in the absorption, scattering, and even emission spectra under the circular polarization bases. A broadband chiroptical effect is highly desired for many passive chiral applications such as pure circular polarizers, chiral imaging, and chiral holography, in which cases the resonances should be avoided. On the other hand, resonant chiroptical responses are particularly needed in many situations requiring strong chiral field enhancement such as chiral sensing and chiral emission. This article reviews the latest research on both broadband and resonant chiral metasurfaces. First, we discuss the basic principle of different types of chiroptical effects including 3D/2D optical chirality and intrinsic/extrinsic optical chirality. Then we review typical means for broadband chiral metasurfaces, and related chiral photonic devices including broadband circular polarizers, chiral imaging and chiral holography. Then, we discuss the interaction between chiral light and matter enhanced by resonant chiral metasurfaces, especially for the chiral bound states in the continuum metasurfaces with ultra-high quality factors, which are particularly important for chiral molecule sensing, and chiral light sources. In the final section, the review concludes with an outlook on future directions in chiral photonics.","PeriodicalId":501711,"journal":{"name":"npj Nanophotonics","volume":" ","pages":"1-22"},"PeriodicalIF":0.0,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s44310-024-00018-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141489087","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-03DOI: 10.1038/s44310-024-00005-w
Hang Lu, Omar Alkhazragi, Yue Wang, Nawal Almaymoni, Wenbo Yan, Wahyu Hendra Gunawan, Heming Lin, Tae-Yong Park, Tien Khee Ng, Boon S. Ooi
Since the invention of the laser, there have been countless applications that were made possible or improved through exploiting its multitude of unique advantages. Most of these advantages are mainly due to the high degree of coherence of the laser light, which makes it directional and spectrally pure. Nevertheless, many fields require a moderate degree of temporal or spatial coherence, making conventional lasers unsuitable for these applications. This has brought about a great interest in partially coherent light sources, especially those based on semiconductor devices, given their efficiency, compactness, and high-speed operation. Here, we review the development of low-coherence semiconductor light sources, including superluminescent diodes, highly multimode lasers, and random lasers, and the wide range of applications in which they have been deployed. We highlight how each of these applications benefsits from a lower degree of coherence in space and/or time. We then discuss future potential applications that can be enabled using new types of low-coherence light.
{"title":"Low-coherence semiconductor light sources: devices and applications","authors":"Hang Lu, Omar Alkhazragi, Yue Wang, Nawal Almaymoni, Wenbo Yan, Wahyu Hendra Gunawan, Heming Lin, Tae-Yong Park, Tien Khee Ng, Boon S. Ooi","doi":"10.1038/s44310-024-00005-w","DOIUrl":"10.1038/s44310-024-00005-w","url":null,"abstract":"Since the invention of the laser, there have been countless applications that were made possible or improved through exploiting its multitude of unique advantages. Most of these advantages are mainly due to the high degree of coherence of the laser light, which makes it directional and spectrally pure. Nevertheless, many fields require a moderate degree of temporal or spatial coherence, making conventional lasers unsuitable for these applications. This has brought about a great interest in partially coherent light sources, especially those based on semiconductor devices, given their efficiency, compactness, and high-speed operation. Here, we review the development of low-coherence semiconductor light sources, including superluminescent diodes, highly multimode lasers, and random lasers, and the wide range of applications in which they have been deployed. We highlight how each of these applications benefsits from a lower degree of coherence in space and/or time. We then discuss future potential applications that can be enabled using new types of low-coherence light.","PeriodicalId":501711,"journal":{"name":"npj Nanophotonics","volume":" ","pages":"1-19"},"PeriodicalIF":0.0,"publicationDate":"2024-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s44310-024-00005-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141246195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Optical metasurfaces that control the light wavefront play an important role in various applications, from imaging to spectroscopy. Over the past decade, metasurfaces-based dynamic optical manipulation has been broadly investigated on diverse reconfigurable mechanisms, providing a footing ground for light control in both spatial and temporal dimensions. Therein, mechanical reconfiguration, as one of the most direct methods, allows for the geometric alteration of constituent meta-atoms through external stimuli, thereby facilitating the evolution of metasurfaces from single function to multifunctional. This review focuses on introducing the primary mechanisms behind current mechanically reconfigurable metasurfaces, including mechanical, electrical, thermal, and optical modulations. Their emerging applications, such as dynamic focusing, image display, beam steering, polarization manipulator, thermal radiation, etc., are briefly highlighted. The main challenges and future development directions are also summarized within this dynamic and rapidly evolving research area, offering insights and future perspectives for advancements in the related fields.
{"title":"Mechanically reconfigurable metasurfaces: fabrications and applications","authors":"Yinghao Zhao, Zhiguang Liu, Chongrui Li, Wenlong Jiao, Senlin Jiang, Xiaowei Li, Jiahua Duan, Jiafang Li","doi":"10.1038/s44310-024-00010-z","DOIUrl":"10.1038/s44310-024-00010-z","url":null,"abstract":"Optical metasurfaces that control the light wavefront play an important role in various applications, from imaging to spectroscopy. Over the past decade, metasurfaces-based dynamic optical manipulation has been broadly investigated on diverse reconfigurable mechanisms, providing a footing ground for light control in both spatial and temporal dimensions. Therein, mechanical reconfiguration, as one of the most direct methods, allows for the geometric alteration of constituent meta-atoms through external stimuli, thereby facilitating the evolution of metasurfaces from single function to multifunctional. This review focuses on introducing the primary mechanisms behind current mechanically reconfigurable metasurfaces, including mechanical, electrical, thermal, and optical modulations. Their emerging applications, such as dynamic focusing, image display, beam steering, polarization manipulator, thermal radiation, etc., are briefly highlighted. The main challenges and future development directions are also summarized within this dynamic and rapidly evolving research area, offering insights and future perspectives for advancements in the related fields.","PeriodicalId":501711,"journal":{"name":"npj Nanophotonics","volume":" ","pages":"1-11"},"PeriodicalIF":0.0,"publicationDate":"2024-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s44310-024-00010-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141246214","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-03DOI: 10.1038/s44310-024-00009-6
Rui Chen, Virat Tara, Minho Choi, Jayita Dutta, Justin Sim, Julian Ye, Zhuoran Fang, Jiajiu Zheng, Arka Majumdar
Programmable photonic integrated circuits (PICs) consisting of reconfigurable on-chip optical components have been creating new paradigms in various applications, such as integrated spectroscopy, multi-purpose microwave photonics, and optical information processing. Among many reconfiguration mechanisms, non-volatile chalcogenide phase-change materials (PCMs) exhibit a promising approach to the future very-large-scale programmable PICs, thanks to their zero static power and large optical index modulation, leading to extremely low energy consumption and ultra-compact footprints. However, the scalability of the current PCM-based programmable PICs is still limited since they are not directly off-the-shelf in commercial photonic foundries now. Here, we demonstrate a scalable platform harnessing the mature and reliable 300 mm silicon photonic fab, assisted by an in-house wide-bandgap PCM (Sb2S3) integration process. We show various non-volatile programmable devices, including micro-ring resonators, Mach-Zehnder interferometers and asymmetric directional couplers, with low loss (~0.0044 dB/µm), large phase shift (~0.012 π/µm) and high endurance (>5000 switching events with little performance degradation). Moreover, we showcase this platform’s capability of handling relatively complex structures such as multiple PIN diode heaters in devices, each independently controlling an Sb2S3 segment. By reliably setting the Sb2S3 segments to fully amorphous or crystalline state, we achieved deterministic multilevel operation. An asymmetric directional coupler with two unequal-length Sb2S3 segments showed the capability of four-level switching, beyond cross-and-bar binary states. We further showed unbalanced Mach-Zehnder interferometers with equal-length and unequal-length Sb2S3 segments, exhibiting reversible switching and a maximum of 5 ( $$N+1,N=4$$ ) and 8 ( $${2}^{N},N=3$$ ) equally spaced operation levels, respectively. This work lays the foundation for future programmable very-large-scale PICs with deterministic programmability.
{"title":"Deterministic quasi-continuous tuning of phase-change material integrated on a high-volume 300-mm silicon photonics platform","authors":"Rui Chen, Virat Tara, Minho Choi, Jayita Dutta, Justin Sim, Julian Ye, Zhuoran Fang, Jiajiu Zheng, Arka Majumdar","doi":"10.1038/s44310-024-00009-6","DOIUrl":"10.1038/s44310-024-00009-6","url":null,"abstract":"Programmable photonic integrated circuits (PICs) consisting of reconfigurable on-chip optical components have been creating new paradigms in various applications, such as integrated spectroscopy, multi-purpose microwave photonics, and optical information processing. Among many reconfiguration mechanisms, non-volatile chalcogenide phase-change materials (PCMs) exhibit a promising approach to the future very-large-scale programmable PICs, thanks to their zero static power and large optical index modulation, leading to extremely low energy consumption and ultra-compact footprints. However, the scalability of the current PCM-based programmable PICs is still limited since they are not directly off-the-shelf in commercial photonic foundries now. Here, we demonstrate a scalable platform harnessing the mature and reliable 300 mm silicon photonic fab, assisted by an in-house wide-bandgap PCM (Sb2S3) integration process. We show various non-volatile programmable devices, including micro-ring resonators, Mach-Zehnder interferometers and asymmetric directional couplers, with low loss (~0.0044 dB/µm), large phase shift (~0.012 π/µm) and high endurance (>5000 switching events with little performance degradation). Moreover, we showcase this platform’s capability of handling relatively complex structures such as multiple PIN diode heaters in devices, each independently controlling an Sb2S3 segment. By reliably setting the Sb2S3 segments to fully amorphous or crystalline state, we achieved deterministic multilevel operation. An asymmetric directional coupler with two unequal-length Sb2S3 segments showed the capability of four-level switching, beyond cross-and-bar binary states. We further showed unbalanced Mach-Zehnder interferometers with equal-length and unequal-length Sb2S3 segments, exhibiting reversible switching and a maximum of 5 ( $$N+1,N=4$$ ) and 8 ( $${2}^{N},N=3$$ ) equally spaced operation levels, respectively. This work lays the foundation for future programmable very-large-scale PICs with deterministic programmability.","PeriodicalId":501711,"journal":{"name":"npj Nanophotonics","volume":" ","pages":"1-9"},"PeriodicalIF":0.0,"publicationDate":"2024-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s44310-024-00009-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141246224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-03DOI: 10.1038/s44310-024-00011-y
Arthur L. Hendriks, Luca Picelli, René P. J. van Veldhoven, Ewold Verhagen, Andrea Fiore
Nano-optomechanical sensors exploit light confinement at the nanoscale to enable very precise measurements of displacement, force, acceleration, and mass. Their application is hampered by the complex optical set-ups or packaging schemes required to couple light to and from the nano-optomechanical resonator. In this work, we present a fiber-coupled nano-optomechanical sensor that requires no coupling optics. This is achieved by directly placing a nano-optomechanical structure, a double membrane photonic crystal (DM-PhC), on the facet of a fiber, using a simple and scalable wafer-to-fiber transfer method. The device is probed in reflection and has a resonance at telecom wavelengths with a relatively broad spectral width of 3–10 nm, which is advantageous for a simple read-out and achieves a displacement imprecision of $$10,{{rm{fm}}}/{sqrt{{rm{Hz}}}}$$ . Using resonant driving and a ringdown measurement, we can induce and monitor mechanical oscillations with an nm-scale amplitude via the fiber, which allows for tracking the mechanical resonant frequency and the mechanical linewidth with imprecisions of 79 and 12 Hz, respectively, at integration times of 4.5 s. We further demonstrate the application of this fiber-tip sensor to the measurement of pressure, using the effect of collisional damping on the mechanical linewidth, leading to the imprecision of $$9times {10}^{-4},{rm{mbar}}$$ with an integration time of 290 s. This combination of optomechanics and fiber-tip sensing may open the way to a new generation of fiber sensors with unprecedented functionality, ultrasmall footprint, and low-cost readout.
{"title":"Nano-optomechanical fiber-tip sensing","authors":"Arthur L. Hendriks, Luca Picelli, René P. J. van Veldhoven, Ewold Verhagen, Andrea Fiore","doi":"10.1038/s44310-024-00011-y","DOIUrl":"10.1038/s44310-024-00011-y","url":null,"abstract":"Nano-optomechanical sensors exploit light confinement at the nanoscale to enable very precise measurements of displacement, force, acceleration, and mass. Their application is hampered by the complex optical set-ups or packaging schemes required to couple light to and from the nano-optomechanical resonator. In this work, we present a fiber-coupled nano-optomechanical sensor that requires no coupling optics. This is achieved by directly placing a nano-optomechanical structure, a double membrane photonic crystal (DM-PhC), on the facet of a fiber, using a simple and scalable wafer-to-fiber transfer method. The device is probed in reflection and has a resonance at telecom wavelengths with a relatively broad spectral width of 3–10 nm, which is advantageous for a simple read-out and achieves a displacement imprecision of $$10,{{rm{fm}}}/{sqrt{{rm{Hz}}}}$$ . Using resonant driving and a ringdown measurement, we can induce and monitor mechanical oscillations with an nm-scale amplitude via the fiber, which allows for tracking the mechanical resonant frequency and the mechanical linewidth with imprecisions of 79 and 12 Hz, respectively, at integration times of 4.5 s. We further demonstrate the application of this fiber-tip sensor to the measurement of pressure, using the effect of collisional damping on the mechanical linewidth, leading to the imprecision of $$9times {10}^{-4},{rm{mbar}}$$ with an integration time of 290 s. This combination of optomechanics and fiber-tip sensing may open the way to a new generation of fiber sensors with unprecedented functionality, ultrasmall footprint, and low-cost readout.","PeriodicalId":501711,"journal":{"name":"npj Nanophotonics","volume":" ","pages":"1-8"},"PeriodicalIF":0.0,"publicationDate":"2024-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s44310-024-00011-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141246221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","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：