Innovations in artificial intelligence have revolutionized various areas,especially optics.The rapid development of novel optoelectronic devices at nanoscale has exhibited the multiple functionalities,high integration...Innovations in artificial intelligence have revolutionized various areas,especially optics.The rapid development of novel optoelectronic devices at nanoscale has exhibited the multiple functionalities,high integration,compactness,fast modulation and scalability,showcasing new breakthroughs of digital optics and optoelectronic processors for intelligent computations.展开更多
This paper presents design and simulation of a switchable radiative cooler that exploits phase transition in vanadium di-oxide to turn on and off in response to temperature.The cooler consists of an emitter and a sola...This paper presents design and simulation of a switchable radiative cooler that exploits phase transition in vanadium di-oxide to turn on and off in response to temperature.The cooler consists of an emitter and a solar reflector separated by a spacer.The emitter and the reflector play a role of emitting energy in mid-infrared and blocking incoming solar energy in ultraviolet to near-infrared regime,respectively.Because of the phase transition of doped vanadium dioxide at room tem-perature,the emitter radiates its thermal energy only when the temperature is above the phase transition temperature.The feasibility of cooling is simulated using real outdoor conditions.We confirme that the switchable cooler can keep a desired temperature,despite change in environmental conditions.展开更多
Ti33O55 films are deposited with the help of an electron beam evaporator for their applications in metasurfaces. The film of subwavelength (632nm) thickness is deposited on a silicon substrate and annealed at 400℃....Ti33O55 films are deposited with the help of an electron beam evaporator for their applications in metasurfaces. The film of subwavelength (632nm) thickness is deposited on a silicon substrate and annealed at 400℃. The ellipsometry result shows a high refractive index above 2.5 with the minimum absorption coefficient in the visible region, which is necessary for high efficiency of transparent metasurfaces. Atomic force microscopy analysis is employed to measure the roughness of the as-deposited films. It is seen from micrographs that the deposited films are very smooth with the minimum roughness to prevent scattering and absorption losses for metasurface devices. The absence of grains and cracks can be seen by scanning electron microscope analysis, which is favorable for electron beam lithography. Fourier transform infrared spectroscopy reveals the transmission and reflection obtained from the film deposited on glass substrates. The as-deposited film shows high transmission above 60%, which is in good agreement with metasurfaces.展开更多
Conventional photonic devices exhibit static optical properties that are design-dependent,including the material’s refractive index and geometrical parameters.However,they still possess attractive optical responses f...Conventional photonic devices exhibit static optical properties that are design-dependent,including the material’s refractive index and geometrical parameters.However,they still possess attractive optical responses for applications and are already exploited in devices across various fields.Hydrogel photonics has emerged as a promising solution in the field of active photonics by providing primarily deformable geometric parameters in response to external stimuli.Over the past few years,various studies have been undertaken to attain stimuli-responsive photonic devices with tunable optical properties.Herein,we focus on the recent advancements in hydrogel-based photonics and micro/nanofabrication techniques for hydrogels.In particular,fabrication techniques for hydrogel photonic devices are categorized into film growth,photolithography(PL),electron-beam lithography(EBL),and nanoimprint lithography(NIL).Furthermore,we provide insights into future directions and prospects for deformable hydrogel photonics,along with their potential practical applications.展开更多
Nanoimprint lithography(NIL)has been utilized to address the manufacturing challenges of high cost and low throughput for optical metasurfaces.To overcome the limitations inherent in conventional imprint resins charac...Nanoimprint lithography(NIL)has been utilized to address the manufacturing challenges of high cost and low throughput for optical metasurfaces.To overcome the limitations inherent in conventional imprint resins characterized by a low refractive index(n),high-n nanocomposites have been introduced to directly serve as meta-atoms.However,comprehensive research on these nanocomposites is notably lacking.In this study,we focus on the composition of high-n zirconium dioxide(ZrO_(2))nanoparticle(NP)concentration and solvents used to produce ultraviolet(UV)metaholograms and quantify the transfer fidelity by the measured conversion efficiency.The utilization of 80 wt%ZrO_(2)NPs in MIBK,MEK,and acetone results in conversion efficiencies of 62.3%,51.4%,and 61.5%,respectively,at a wavelength of 325 nm.The analysis of the solvent composition and NP concentration can further enhance the manufacturing capabilities of high-n nanocomposites in NIL,enabling potential practical use of optical metasurfaces.展开更多
We present an azimuthal-rotation-controlled dynamic nanoinscribing(ARC-DNI)process for continuous and scalable fabrication of asymmetric nanograting structures with tunable periods and shape profiles.A sliced edge of ...We present an azimuthal-rotation-controlled dynamic nanoinscribing(ARC-DNI)process for continuous and scalable fabrication of asymmetric nanograting structures with tunable periods and shape profiles.A sliced edge of a nanograting mold,which typically has a rectangular grating profile,slides over a polymeric substrate to induce its burrfree plastic deformation into a linear nanopattern.During this continuous nanoinscribing process,the“azimuthal angle,”that is,the angle between the moving direction of the polymeric substrate and the mold’s grating line orientation,can be controlled to tailor the period,geometrical shape,and profile of the inscribed nanopatterns.By modulating the azimuthal angle,along with other important ARC-DNI parameters such as temperature,force,and inscribing speed,we demonstrate that the mold-opening profile and temperature-and time-dependent viscoelastic polymer reflow can be controlled to fabricate asymmetric,blazed,and slanted nanogratings that have diverse geometrical profiles such as trapezoidal,triangular,and parallelogrammatic.Finally,period-and profile-tunable ARC-DNI can be utilized for the practical fabrication of diverse optical devices,as is exemplified by asymmetric diffractive optical elements in this study.展开更多
Metasurfaces have been continuously garnering attention in both scientific and industrial fields,owing to their unprecedented wavefront manipulation capabilities using arranged subwavelength artificial structures.To d...Metasurfaces have been continuously garnering attention in both scientific and industrial fields,owing to their unprecedented wavefront manipulation capabilities using arranged subwavelength artificial structures.To date,research has mainly focused on the full control of electromagnetic characteristics,including polarization,phase,amplitude,and even frequencies.Consequently,versatile possibilities of electromagnetic wave control have been achieved,yielding practical optical components such as metalenses,beam-steerers,metaholograms,and sensors.Current research is now focused on integrating the aforementioned metasurfaces with other standard optical components(e.g.,light-emitting diodes,charged-coupled devices,micro-electro-mechanical systems,liquid crystals,heaters,refractive optical elements,planar waveguides,optical fibers,etc.)for commercialization with miniaturization trends of optical devices.Herein,this review describes and classifies metasurface-integrated optical components,and subsequently discusses their promising applications with metasurface-integrated optical platforms including those of augmented/virtual reality,light detection and ranging,and sensors.In conclusion,this review presents several challenges and prospects that are prevalent in the field in order to accelerate the commercialization of metasurfaces-integrated optical platforms.展开更多
A single-step printable platform for ultraviolet(UV)metasurfaces is introduced to overcome both the scarcity of low-loss UV materials and manufacturing limitations of high cost and low throughput.By dispersing zirconi...A single-step printable platform for ultraviolet(UV)metasurfaces is introduced to overcome both the scarcity of low-loss UV materials and manufacturing limitations of high cost and low throughput.By dispersing zirconium dioxide(ZrO_(2))nanoparticles in a UV-curable resin,ZrO_(2)nanoparticle-embedded-resin(nano-PER)is developed as a printable material which has a high refractive index and low extinction coefficient from near-UV to deep-UV.In ZrO_(2)nano-PER,the UV-curable resin enables direct pattern transfer and ZrO_(2)nanoparticles increase the refractive index of the composite while maintaining a large bandgap.With this concept,UV metasurfaces can be fabricated in a single step by nanoimprint lithography.As a proof of concept,UV metaholograms operating in near-UV and deep-UV are experimentally demonstrated with vivid and clear holographic images.The proposed method enables repeat and rapid manufacturing of UV metasurfaces,and thus will bring UV metasurfaces more close to real life.展开更多
In 1992,Professor Allen’s paper published in Physical Review A indi-cated that laser light with a Laguerre-Gaussian amplitude distribution has an orbital angular momentum(OAM).Since then,conceptual stud-ies on OAM of...In 1992,Professor Allen’s paper published in Physical Review A indi-cated that laser light with a Laguerre-Gaussian amplitude distribution has an orbital angular momentum(OAM).Since then,conceptual stud-ies on OAM of photons have been attracting continual attention in physics and optics communities.In recent years,we have witnessed the birth and fast development of many break-through technologies driven by the concept of OAM,from advanced light-field manipulation to super-resolution imaging,classical and quantum optical communi-cations,and many others.展开更多
Advancements in micro/nanofabrication have enabled the realization of practical micro/nanoscale photonic devices such as absorbers,solar cells,metalenses,and metaholograms.Although the performance of these photonic de...Advancements in micro/nanofabrication have enabled the realization of practical micro/nanoscale photonic devices such as absorbers,solar cells,metalenses,and metaholograms.Although the performance of these photonic devices has been improved by enhancing the design flexibility of structural materials through advanced fabrication methods,achieving large-area and high-throughput fabrication of tiny structural materials remains a challenge.In this aspect,various technologies have been investigated for realizing the mass production of practical devices consisting of micro/nanostructural materials.This review describes the recent advancements in soft lithography,colloidal self-assembly,and block copolymer self-assembly,which are promising methods suitable for commercialization of photonic applications.In addition,we introduce low-cost and large-scale techniques realizing micro/nano devices with specific examples such as display technology and sensors.The inferences presented in this review are expected to function as a guide for promising methods of accelerating the mass production of various sub-wavelength-scale photonic devices.展开更多
Photonics research is a rapidly growing field that has found applications in various aspects of our lives,ran-ging from communication to medical imaging1-5.Col-laborative innovation between academia and industry has b...Photonics research is a rapidly growing field that has found applications in various aspects of our lives,ran-ging from communication to medical imaging1-5.Col-laborative innovation between academia and industry has been a driving force behind the significant advances in photonics research in South Korea.In this special issue,we present cutting-edge research in photonics,highlighting the importance of collaboration between academia and industry(Fig.1).展开更多
Structural coloration,the production of color with nanoscale structures,has steadily gained attention owing to numerous advantages such as environmental friendliness,long-term durability,and vivid coloration compared ...Structural coloration,the production of color with nanoscale structures,has steadily gained attention owing to numerous advantages such as environmental friendliness,long-term durability,and vivid coloration compared to conventional chemical pigments.1–3 In addition,recent de-velopments in the field of nanofabrication have led to an increase in research on structural coloration with sophisticated artificial materials,known as metamaterials.展开更多
Torsional optomechanics,which involves the transfer of angular mo-mentum from light to matter,has been a vibrant research area since Beth’s pioneering contribution in 1935.Beth proposed a method to measure the transf...Torsional optomechanics,which involves the transfer of angular mo-mentum from light to matter,has been a vibrant research area since Beth’s pioneering contribution in 1935.Beth proposed a method to measure the transfer of spin angular momentum using a torsional pen-dulum,1 laying the foundation for classical and quantum optomechanics related to particle levitation,trapping,and cooling in modern optics.展开更多
Metasurfaces have opened the door to next-generation optical devices due to their ability to dramatically modulate electromagnetic waves at will using periodically arranged nanostructures.However,metasurfaces typicall...Metasurfaces have opened the door to next-generation optical devices due to their ability to dramatically modulate electromagnetic waves at will using periodically arranged nanostructures.However,metasurfaces typically have static optical responses with fixed geometries of nanostructures,which poses challenges for implementing transition to technology by replacing conventional optical components.To solve this problem,liquid crystals(LCs)have been actively employed for designing tunable metasurfaces using their adjustable birefringent in real time.Here,we review recent studies on LCpowered tunable metasurfaces,which are categorized as wavefront tuning and spectral tuning.Compared to numerous reviews on tunable metasurfaces,this review intensively explores recent development of LC-integrated metasurfaces.At the end of this review,we briefly introduce the latest research trends on LC-powered metasurfaces and suggest further directions for improving LCs.We hope that this review will accelerate the development of new and innovative LC-powered devices.展开更多
Chirality arises universally across many different fields.Recent advancements in artificial nanomaterials have demonstrated chiroptical responses that far exceed those found in natural materials.Chiroptical phenomena ...Chirality arises universally across many different fields.Recent advancements in artificial nanomaterials have demonstrated chiroptical responses that far exceed those found in natural materials.Chiroptical phenomena are complicated processes that involve transitions between states with opposite parities,and solid interpretations of these observations are yet to be clearly provided.In this review,we present a comprehensive overview of the theoretical aspects of chirality in light,nanostructures,and nanosystems and their chiroptical interactions.Descriptions of observed chiroptical phenomena based on these fundamentals are intensively discussed.We start with the strong intrinsic and extrinsic chirality in plasmonic nanoparticle systems,followed by enantioselective sensing and optical manipulation,and then conclude with orbital angular momentum-dependent responses.This review will be helpful for understanding the mechanisms behind chiroptical phenomena based on underlying chiral properties and useful for interpreting chiroptical systems for further studies.展开更多
Over the past decade,topology has emerged as a major branch in broad areas of physics,from atomic lattices to condensed matter.In particular,topology has received significant attention in photonics because light waves...Over the past decade,topology has emerged as a major branch in broad areas of physics,from atomic lattices to condensed matter.In particular,topology has received significant attention in photonics because light waves can serve as a platform to investigate nontrivial bulk and edge physics with the aid of carefully engineered photonic crystals and metamaterials.Simultaneously,photonics provides enriched physics that arises from spin-1 vectorial electromagnetic fields.Here,we review recent progress in the growing field of topological photonics in three parts.The first part is dedicated to the basics of topological band theory and introduces various two-dimensional topological phases.The second part reviews three-dimensional topological phases and numerous approaches to achieve them in photonics.Last,we present recently emerging fields in topological photonics that have not yet been reviewed.This part includes topological degeneracies in nonzero dimensions,unidirectional Maxwellian spin waves,higher-order photonic topological phases,and stacking of photonic crystals to attain layer pseudospin.In addition to the various approaches for realizing photonic topological phases,we also discuss the interaction between light and topological matter and the efforts towards practical applications of topological photonics.展开更多
Metasurfaces have attracted great attention due to their ability to manipulate the phase,amplitude,and polarization of light in a compact form.Tunable metasurfaces have been investigated recently through the integrati...Metasurfaces have attracted great attention due to their ability to manipulate the phase,amplitude,and polarization of light in a compact form.Tunable metasurfaces have been investigated recently through the integration with mechanically moving components and electrically tunable elements.Two interesting applications,in particular,are to vary the focal point of metalenses and to switch between holographic images.We present the recent progress on tunable metasurfaces focused on metalenses and metaholograms,including the basic working principles,advantages,and disadvantages of each working mechanism.We classify the tunable stimuli based on the light source and electrical bias,as well as others such as thermal and mechanical modulation.We conclude by summarizing the recent progress of metalenses and metaholograms,and providing our perspectives for the further development of tunable metasurfaces.展开更多
Metasurfaces are composed of periodic subwavelength nanostructures and exhibit optical properties that are not found in nature.They have been widely investigated for optical applications such as holograms,wavefront sh...Metasurfaces are composed of periodic subwavelength nanostructures and exhibit optical properties that are not found in nature.They have been widely investigated for optical applications such as holograms,wavefront shaping,and structural color printing,however,electron-beam lithography is not suitable to produce large-area metasurfaces because of the high fabrication cost and low productivity.Although alternative optical technologies,such as holographic lithography and plasmonic lithography,can overcome these drawbacks,such methods are still constrained by the optical diffraction limit.To break through this fundamental problem,mechanical nanopatteming processes have been actively studied in many fields,with nanoimprint lithography(NIL)coming to the forefront.Since NIL replicates the nanopattem of the mold regardless of the diffraction limit,NIL can achieve sufficiently high productivity and patterning resolution,giving rise to an explosive development in the fabrication of metasurfaces.In this review,we focus on various NIL technologies for the manufacturing of metasurfaces.First,we briefly describe conventional NIL and then present various NIL methods for the scalable fabrication of metasurfaces.We also discuss recent applications of NIL in the realization of metasurfaces.Finally,we conclude with an outlook on each method and suggest perspectives for future research on the high-throughput fabrication of active metasurfaces.展开更多
Metasurfaces consisting of subwavelength structures,so-called meta-atoms,have steadily attracted considerable attention for advanced holography due to their advantages in terms of high-resolution holographic images,la...Metasurfaces consisting of subwavelength structures,so-called meta-atoms,have steadily attracted considerable attention for advanced holography due to their advantages in terms of high-resolution holographic images,large field of view,and compact device volume.In contrast to conventional holographic displays using bulky conventional diffractive optical elements,metasurface holography enables arbitrary complex wavefront shaping with a much smaller footprint.In this review,we classify metasurface holography according to the meta-atom design methodologies,which can further expand hologram functionalities.We describe light-matter interactions,particularly in metasurface systems,using the relevant the Jones matrix to rigorously explain modulations of the amplitude,phase,and polarization of light.Six different types of metaatoms are presented,and the corresponding achievable wavefronts that form the holographic images in the far-field are also provided.Such a simple classification will give a straightforward approach to design and further realize advanced metasurface holographic devices.展开更多
With the rapid progress in computer science,including artificial intelligence,big data and cloud computing,full-space spot generation can be pivotal to many practical applications,such as facial recognition,motion det...With the rapid progress in computer science,including artificial intelligence,big data and cloud computing,full-space spot generation can be pivotal to many practical applications,such as facial recognition,motion detection,augmented reality,etc.These opportunities may be achieved by using diffractive optical elements(DOEs)or light detection and ranging(LIDAR).However,DOEs suffer from intrinsic limitations,such as demanding depth-controlled fabrication techniques,large thicknesses(more than the wavelength),Lambertian operation only in half space,etc.LIDAR nevertheless relies on complex and bulky scanning systems,which hinders the miniaturization of the spot generator.Here,inspired by a Lambertian scatterer,we report a Hermitian-conjugate metasurface scrambling the incident light to a cloud of random points in full space with compressed information density,functioning in both transmission and reflection spaces.Over 4044 random spots are experimentally observed in the entire space,covering angles at nearly 90°.Our scrambling metasurface is made of amorphous silicon with a uniform subwavelength height,a nearly continuous phase coverage,a lightweight,flexible design,and low-heat dissipation.Thus,it may be mass produced by and integrated into existing semiconductor foundry designs.Our work opens important directions for emerging 3D recognition sensors,such as motion sensing,facial recognition,and other applications.展开更多
文摘Innovations in artificial intelligence have revolutionized various areas,especially optics.The rapid development of novel optoelectronic devices at nanoscale has exhibited the multiple functionalities,high integration,compactness,fast modulation and scalability,showcasing new breakthroughs of digital optics and optoelectronic processors for intelligent computations.
基金financially supported by the Green Science program funded by POSCOthe National Research Foundation(NRF)grants(NRF2019R1A2C3003129,CAMM-2019M3A6B3030637,NRF-2019R1A5A8080290,and NRF-2018M3D1A1058997)funded by the Ministry of Science and ICT,Republic of Korea+2 种基金the Global Ph.D.fellowship(NRF-2017H1A2A1043204)from the Ministry of Education,Republic of Koreathe PIURI fellowship funded by POSTECHa fellowship from Hyundai Motor Chung Mong-Koo Foundation。
文摘This paper presents design and simulation of a switchable radiative cooler that exploits phase transition in vanadium di-oxide to turn on and off in response to temperature.The cooler consists of an emitter and a solar reflector separated by a spacer.The emitter and the reflector play a role of emitting energy in mid-infrared and blocking incoming solar energy in ultraviolet to near-infrared regime,respectively.Because of the phase transition of doped vanadium dioxide at room tem-perature,the emitter radiates its thermal energy only when the temperature is above the phase transition temperature.The feasibility of cooling is simulated using real outdoor conditions.We confirme that the switchable cooler can keep a desired temperature,despite change in environmental conditions.
基金Information Technology University of the Punjab, Lahore, Pakistan for financial supportthe financial support by Engineering Research Center Program(NRF-2015R1A5A1037668)+1 种基金global Ph.D. fellowship(NRF-2016H1A2A1906519)the KRF fellowship(NRF-2017H1D3A1A02011379)through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning (MSIP) of Korean government
文摘Ti33O55 films are deposited with the help of an electron beam evaporator for their applications in metasurfaces. The film of subwavelength (632nm) thickness is deposited on a silicon substrate and annealed at 400℃. The ellipsometry result shows a high refractive index above 2.5 with the minimum absorption coefficient in the visible region, which is necessary for high efficiency of transparent metasurfaces. Atomic force microscopy analysis is employed to measure the roughness of the as-deposited films. It is seen from micrographs that the deposited films are very smooth with the minimum roughness to prevent scattering and absorption losses for metasurface devices. The absence of grains and cracks can be seen by scanning electron microscope analysis, which is favorable for electron beam lithography. Fourier transform infrared spectroscopy reveals the transmission and reflection obtained from the film deposited on glass substrates. The as-deposited film shows high transmission above 60%, which is in good agreement with metasurfaces.
基金supported by the Samsung Research Funding&Incubation Center for Future Technology grants(SRFC-IT1901-52)funded by Samsung Electronics,the POSCO-POSTECH-RIST Convergence Research Center program funded by POSCO,and the National Research Foundation(NRF)grant(NRF-2022M3C1A3081312)funded by the Ministry of Science and ICT of the Korean government.B.K.acknowledges the NRF Ph.D.fellowship(NRF2022R1A6A3A13066244)funded by the Ministry of Education of the Korean government.
文摘Conventional photonic devices exhibit static optical properties that are design-dependent,including the material’s refractive index and geometrical parameters.However,they still possess attractive optical responses for applications and are already exploited in devices across various fields.Hydrogel photonics has emerged as a promising solution in the field of active photonics by providing primarily deformable geometric parameters in response to external stimuli.Over the past few years,various studies have been undertaken to attain stimuli-responsive photonic devices with tunable optical properties.Herein,we focus on the recent advancements in hydrogel-based photonics and micro/nanofabrication techniques for hydrogels.In particular,fabrication techniques for hydrogel photonic devices are categorized into film growth,photolithography(PL),electron-beam lithography(EBL),and nanoimprint lithography(NIL).Furthermore,we provide insights into future directions and prospects for deformable hydrogel photonics,along with their potential practical applications.
基金supported by the POSCO-POSTECH-RIST Convergence Research Center program funded by POSCO,the National Research Foundation(NRF)grants(NRF-2022M3C1A3081312,NRF-2019R1A5A8080290,NRF-2021M3H4A1A04086554)funded by the Ministry of Science and ICT(MSIT)of the Korean governmentthe Korea Evaluation Institute of Industrial Technology(KEIT)grant(no.1415179744/20019169,Alchemist project)funded by the Ministry of Trade,Industry and Energy(MOTIE)of the Korean governmentT.B.acknowledges the Institute of Information&Communications Technology Planning&Evaluation(IITP)grant(no.2019-0-01906,the POSTECH Artificial Intelligence Graduate School program)funded by the MSIT of the Korean government。
文摘Nanoimprint lithography(NIL)has been utilized to address the manufacturing challenges of high cost and low throughput for optical metasurfaces.To overcome the limitations inherent in conventional imprint resins characterized by a low refractive index(n),high-n nanocomposites have been introduced to directly serve as meta-atoms.However,comprehensive research on these nanocomposites is notably lacking.In this study,we focus on the composition of high-n zirconium dioxide(ZrO_(2))nanoparticle(NP)concentration and solvents used to produce ultraviolet(UV)metaholograms and quantify the transfer fidelity by the measured conversion efficiency.The utilization of 80 wt%ZrO_(2)NPs in MIBK,MEK,and acetone results in conversion efficiencies of 62.3%,51.4%,and 61.5%,respectively,at a wavelength of 325 nm.The analysis of the solvent composition and NP concentration can further enhance the manufacturing capabilities of high-n nanocomposites in NIL,enabling potential practical use of optical metasurfaces.
基金supported by grants from the Commercialization Promotion Agency for R&D Outcomes(COMPA-2022-URE-09)the Korea Industrial Technology Association(KOITA-RND3-2022-04)the National Research Foundation of Korea(NRF-2022M3C1A3081178(Ministry of Science and ICT)and NRF-2022R1I1A2073224(Ministry of Education))funded by the Korean Government。
文摘We present an azimuthal-rotation-controlled dynamic nanoinscribing(ARC-DNI)process for continuous and scalable fabrication of asymmetric nanograting structures with tunable periods and shape profiles.A sliced edge of a nanograting mold,which typically has a rectangular grating profile,slides over a polymeric substrate to induce its burrfree plastic deformation into a linear nanopattern.During this continuous nanoinscribing process,the“azimuthal angle,”that is,the angle between the moving direction of the polymeric substrate and the mold’s grating line orientation,can be controlled to tailor the period,geometrical shape,and profile of the inscribed nanopatterns.By modulating the azimuthal angle,along with other important ARC-DNI parameters such as temperature,force,and inscribing speed,we demonstrate that the mold-opening profile and temperature-and time-dependent viscoelastic polymer reflow can be controlled to fabricate asymmetric,blazed,and slanted nanogratings that have diverse geometrical profiles such as trapezoidal,triangular,and parallelogrammatic.Finally,period-and profile-tunable ARC-DNI can be utilized for the practical fabrication of diverse optical devices,as is exemplified by asymmetric diffractive optical elements in this study.
基金This work was financially supported by the POSCO-POSTECH-RIST Convergence Research Center program funded by POSCOthe Samsung Research Funding&Incubation Center for Future Technology grant(SRFC-IT1901-52)funded by Samsung Electronicsthe National Research Foundation(NRF)grants(NRF-2022M3C1A3081312,NRF-2022M3H4A1A02074314,NRF-2022M3H4A1A02085335,NRF-2021K1A3A1A17086079,NRF-2021K2A9A2A15000174,NRF-2019R1A2C3003129,NRF-2019R1A5A8080290,CAMM-2019M3A6B3030637)funded by the Ministry of Science and ICT of the Korean government.
文摘Metasurfaces have been continuously garnering attention in both scientific and industrial fields,owing to their unprecedented wavefront manipulation capabilities using arranged subwavelength artificial structures.To date,research has mainly focused on the full control of electromagnetic characteristics,including polarization,phase,amplitude,and even frequencies.Consequently,versatile possibilities of electromagnetic wave control have been achieved,yielding practical optical components such as metalenses,beam-steerers,metaholograms,and sensors.Current research is now focused on integrating the aforementioned metasurfaces with other standard optical components(e.g.,light-emitting diodes,charged-coupled devices,micro-electro-mechanical systems,liquid crystals,heaters,refractive optical elements,planar waveguides,optical fibers,etc.)for commercialization with miniaturization trends of optical devices.Herein,this review describes and classifies metasurface-integrated optical components,and subsequently discusses their promising applications with metasurface-integrated optical platforms including those of augmented/virtual reality,light detection and ranging,and sensors.In conclusion,this review presents several challenges and prospects that are prevalent in the field in order to accelerate the commercialization of metasurfaces-integrated optical platforms.
基金supported by the POSCO-POSTECH-RIST Convergence Research Center program funded by POSCO,a university R&D program funded by Samsung Electronics,and the National Research Foundation(NRF)grants(NRF-2022M3C1A3081312,NRF-2022M3H4A1A02074314,NRF-2021K1A3A1A17086079,NRF-2021K2A9A2A15000174,CAMM-2019M3A6B3030637,NRF-2019R1A5A8080290)funded by the Ministry of Science and ICT(MSIT)of the Korean government.
文摘A single-step printable platform for ultraviolet(UV)metasurfaces is introduced to overcome both the scarcity of low-loss UV materials and manufacturing limitations of high cost and low throughput.By dispersing zirconium dioxide(ZrO_(2))nanoparticles in a UV-curable resin,ZrO_(2)nanoparticle-embedded-resin(nano-PER)is developed as a printable material which has a high refractive index and low extinction coefficient from near-UV to deep-UV.In ZrO_(2)nano-PER,the UV-curable resin enables direct pattern transfer and ZrO_(2)nanoparticles increase the refractive index of the composite while maintaining a large bandgap.With this concept,UV metasurfaces can be fabricated in a single step by nanoimprint lithography.As a proof of concept,UV metaholograms operating in near-UV and deep-UV are experimentally demonstrated with vivid and clear holographic images.The proposed method enables repeat and rapid manufacturing of UV metasurfaces,and thus will bring UV metasurfaces more close to real life.
文摘In 1992,Professor Allen’s paper published in Physical Review A indi-cated that laser light with a Laguerre-Gaussian amplitude distribution has an orbital angular momentum(OAM).Since then,conceptual stud-ies on OAM of photons have been attracting continual attention in physics and optics communities.In recent years,we have witnessed the birth and fast development of many break-through technologies driven by the concept of OAM,from advanced light-field manipulation to super-resolution imaging,classical and quantum optical communi-cations,and many others.
基金supported by the POSCOPOSTECH-RIST Convergence Research Center program funded by POSCO,and the National Research Foundation (NRF)grant (NRF-2022M3C1A3081312)Y.Y.and D.K.O.acknowledge Hyundai Motor Chung Mong-Koo fellowships.Y.Y.acknowledges the NRF fellowship (NRF-2021R1A6A3A13038935)funded by the Ministry of Education,Republic of Korea.H.K.and N.J.acknowledge POSTECHIAN fellowships.
文摘Advancements in micro/nanofabrication have enabled the realization of practical micro/nanoscale photonic devices such as absorbers,solar cells,metalenses,and metaholograms.Although the performance of these photonic devices has been improved by enhancing the design flexibility of structural materials through advanced fabrication methods,achieving large-area and high-throughput fabrication of tiny structural materials remains a challenge.In this aspect,various technologies have been investigated for realizing the mass production of practical devices consisting of micro/nanostructural materials.This review describes the recent advancements in soft lithography,colloidal self-assembly,and block copolymer self-assembly,which are promising methods suitable for commercialization of photonic applications.In addition,we introduce low-cost and large-scale techniques realizing micro/nano devices with specific examples such as display technology and sensors.The inferences presented in this review are expected to function as a guide for promising methods of accelerating the mass production of various sub-wavelength-scale photonic devices.
基金supported by the POSCO-POSTECH-RIST Convergence Research Center program funded by POSCO,the Samsung Advanced Institute of Technology(SAIT)visiting scholar fellowship funded by Samsung Electronics,and the National Research Foundation(NRF)grant(NRF-2022M3C1A3081312)funded by the Ministry of Science and ICT(MSIT)of the Korean government.T.B.acknowledges the Institute of Information&Communications Technology Planning&Evaluation(IITP)grant(No.2019-0-01906,the POSTECH Artificial Intelligence Graduate School program)funded by the MSIT of the Korean government,and the POSTECH PIURI fellowship.Y.Y.acknowledges the Hyundai Motor Chung Mong-Koo fellowship。
文摘Photonics research is a rapidly growing field that has found applications in various aspects of our lives,ran-ging from communication to medical imaging1-5.Col-laborative innovation between academia and industry has been a driving force behind the significant advances in photonics research in South Korea.In this special issue,we present cutting-edge research in photonics,highlighting the importance of collaboration between academia and industry(Fig.1).
基金financially supported by the POSCO-POSTECHRIST Convergence Research Center program funded by POSCOthe National Research Foundation (NRF) grant (NRF2022M3C1A3081312) funded by the Ministry of Science and ICT of the Korean government+3 种基金the Hyundai Motor Chung Mong-Koo fellowshipthe NRF fellowship (NRF2021R1A6A3A13038935) funded by the Ministry of Education of the Korean governmentthe Institute of Information & Communications Technology Planning & Evaluation (IITP) grant (No. 2019-0-01906, the POSTECH Artificial Intelligence Graduate School program) funded by the MSIT of the Korean governmentthe POSTECH PIURI fellowship.
文摘Structural coloration,the production of color with nanoscale structures,has steadily gained attention owing to numerous advantages such as environmental friendliness,long-term durability,and vivid coloration compared to conventional chemical pigments.1–3 In addition,recent de-velopments in the field of nanofabrication have led to an increase in research on structural coloration with sophisticated artificial materials,known as metamaterials.
基金This work was financially supported by the POSCO-POSTECHRIST Convergence Research Center program funded by POSCO,and the National Research Foundation(NRF)grant(NRF2022M3C1A3081312)funded by the Ministry of Science and ICT(MSIT)of the Korean governmentJ.J.acknowledges the NRF Sejong Science fellowship(NRF-RS-2023-00209560)funded by the Ministry of Science and ICT(MSIT)of the Korean government。
文摘Torsional optomechanics,which involves the transfer of angular mo-mentum from light to matter,has been a vibrant research area since Beth’s pioneering contribution in 1935.Beth proposed a method to measure the transfer of spin angular momentum using a torsional pen-dulum,1 laying the foundation for classical and quantum optomechanics related to particle levitation,trapping,and cooling in modern optics.
基金supported by the POSCO-POSTECH-RIST Convergence Research Center program funded by POSCO,the Samsung Research Funding&Incubation Center for Future Technology grant(SRFC-IT1901-52)funded by Samsung Electronicsthe National Research Foundation(NRF)grants(NRF-2022M3C1A3081312,NRF-2022M3H4A1A-02074314,NRF-2022M3H4A1A02046445,NRF-2021M3H4A1A04086357,NRF-2019R1A5A8080290,RS-2024-00356928,RS-2023-00283667)funded by the Ministry of Science and ICT of the Korean governmentthe Korea Evaluation Institute of Industrial Technology(KEIT)grant(No.1415185027/20019169,Alchemist project)funded by the Ministry of Trade,Industry and Energy(MOTIE)of the Korean government.H.Kim and J.Kim acknowledge the POSTECH Alchemist fellowship,the Asan Foundation Biomedical Science fellowship,and Presidential Science fellowship funded by the MSIT of the Korean government.
文摘Metasurfaces have opened the door to next-generation optical devices due to their ability to dramatically modulate electromagnetic waves at will using periodically arranged nanostructures.However,metasurfaces typically have static optical responses with fixed geometries of nanostructures,which poses challenges for implementing transition to technology by replacing conventional optical components.To solve this problem,liquid crystals(LCs)have been actively employed for designing tunable metasurfaces using their adjustable birefringent in real time.Here,we review recent studies on LCpowered tunable metasurfaces,which are categorized as wavefront tuning and spectral tuning.Compared to numerous reviews on tunable metasurfaces,this review intensively explores recent development of LC-integrated metasurfaces.At the end of this review,we briefly introduce the latest research trends on LC-powered metasurfaces and suggest further directions for improving LCs.We hope that this review will accelerate the development of new and innovative LC-powered devices.
基金financially supported by the National Research Foundation(NRF)grants(NRF-2019R1A2C3003129,CAMM-2019M3A6B3030637,NRF-2019R1A5A8080290,NRF-2018M3D1A1058997)funded by the Ministry of Science and ICT of the Korean government+2 种基金the Global Ph.D.fellowship(NRF-2017H1A2A1043204)funded by the Ministrty of Education of the Korean governmenta fellowship from the Hyundai Motor Chung Mong-Koo Foundation.
文摘Chirality arises universally across many different fields.Recent advancements in artificial nanomaterials have demonstrated chiroptical responses that far exceed those found in natural materials.Chiroptical phenomena are complicated processes that involve transitions between states with opposite parities,and solid interpretations of these observations are yet to be clearly provided.In this review,we present a comprehensive overview of the theoretical aspects of chirality in light,nanostructures,and nanosystems and their chiroptical interactions.Descriptions of observed chiroptical phenomena based on these fundamentals are intensively discussed.We start with the strong intrinsic and extrinsic chirality in plasmonic nanoparticle systems,followed by enantioselective sensing and optical manipulation,and then conclude with orbital angular momentum-dependent responses.This review will be helpful for understanding the mechanisms behind chiroptical phenomena based on underlying chiral properties and useful for interpreting chiroptical systems for further studies.
基金financially supported by the National Research Foundation(NRF)grants(NRF-2019R1A2C3003129,CAMM-2019M3A6B3030637,NRF-2019R1A5A8080290,NRF-2018M3D1A1058997)funded by the Ministry of Science and ICT(MSIT)of the Korean governmentthe Global Ph.D.fellowship(NRF-2017H1A2A1043204)funded by the Ministry of Education of the Korean government.
文摘Over the past decade,topology has emerged as a major branch in broad areas of physics,from atomic lattices to condensed matter.In particular,topology has received significant attention in photonics because light waves can serve as a platform to investigate nontrivial bulk and edge physics with the aid of carefully engineered photonic crystals and metamaterials.Simultaneously,photonics provides enriched physics that arises from spin-1 vectorial electromagnetic fields.Here,we review recent progress in the growing field of topological photonics in three parts.The first part is dedicated to the basics of topological band theory and introduces various two-dimensional topological phases.The second part reviews three-dimensional topological phases and numerous approaches to achieve them in photonics.Last,we present recently emerging fields in topological photonics that have not yet been reviewed.This part includes topological degeneracies in nonzero dimensions,unidirectional Maxwellian spin waves,higher-order photonic topological phases,and stacking of photonic crystals to attain layer pseudospin.In addition to the various approaches for realizing photonic topological phases,we also discuss the interaction between light and topological matter and the efforts towards practical applications of topological photonics.
基金financially supported by the POSCO-POSTECH-RIST Convergence Research Center program funded by POSCOthe National Research Foundation (NRF) grants (Grant Nos. NRF2019R1A2C3003129, CAMM-2019M3A6B3030637, and NRF-2019R1A5A8080290) funded by the Ministry of Science and ICT, Republic of Korea+1 种基金the Hyundai Motor Chung Mong-Koo fellowshipthe NRF fellowship (Grant No. NRF-2021R1A6A3A13038935) funded by the Ministry of Education, Republic of Korea
文摘Metasurfaces have attracted great attention due to their ability to manipulate the phase,amplitude,and polarization of light in a compact form.Tunable metasurfaces have been investigated recently through the integration with mechanically moving components and electrically tunable elements.Two interesting applications,in particular,are to vary the focal point of metalenses and to switch between holographic images.We present the recent progress on tunable metasurfaces focused on metalenses and metaholograms,including the basic working principles,advantages,and disadvantages of each working mechanism.We classify the tunable stimuli based on the light source and electrical bias,as well as others such as thermal and mechanical modulation.We conclude by summarizing the recent progress of metalenses and metaholograms,and providing our perspectives for the further development of tunable metasurfaces.
基金the National Research Foundation(NRP)grant(NRF-2019R1A2C3003129)flinded by the Ministry of Science and ICT,Republic of Korea.T.L.acknowledges the NRF Global Ph.D.fellowship(NRF-2019H1 A2A 1076295)funded by the Ministry of Education,Republic of Korea.
文摘Metasurfaces are composed of periodic subwavelength nanostructures and exhibit optical properties that are not found in nature.They have been widely investigated for optical applications such as holograms,wavefront shaping,and structural color printing,however,electron-beam lithography is not suitable to produce large-area metasurfaces because of the high fabrication cost and low productivity.Although alternative optical technologies,such as holographic lithography and plasmonic lithography,can overcome these drawbacks,such methods are still constrained by the optical diffraction limit.To break through this fundamental problem,mechanical nanopatteming processes have been actively studied in many fields,with nanoimprint lithography(NIL)coming to the forefront.Since NIL replicates the nanopattem of the mold regardless of the diffraction limit,NIL can achieve sufficiently high productivity and patterning resolution,giving rise to an explosive development in the fabrication of metasurfaces.In this review,we focus on various NIL technologies for the manufacturing of metasurfaces.First,we briefly describe conventional NIL and then present various NIL methods for the scalable fabrication of metasurfaces.We also discuss recent applications of NIL in the realization of metasurfaces.Finally,we conclude with an outlook on each method and suggest perspectives for future research on the high-throughput fabrication of active metasurfaces.
基金Hyundai Motor Group,Grant/Award Number:Hyundai Motor Chung Mong-Koo fellowshipLG Display,Grant/Award Number:LGD-SNU incubation programNational Research Foundation of Korea,Grant/Award Numbers:CAMM-2019M3A6B3030637,NRF-2019R1A2C3003129,NRF-2019R1A5A8080290,NRF-2021R1C1C2004291。
文摘Metasurfaces consisting of subwavelength structures,so-called meta-atoms,have steadily attracted considerable attention for advanced holography due to their advantages in terms of high-resolution holographic images,large field of view,and compact device volume.In contrast to conventional holographic displays using bulky conventional diffractive optical elements,metasurface holography enables arbitrary complex wavefront shaping with a much smaller footprint.In this review,we classify metasurface holography according to the meta-atom design methodologies,which can further expand hologram functionalities.We describe light-matter interactions,particularly in metasurface systems,using the relevant the Jones matrix to rigorously explain modulations of the amplitude,phase,and polarization of light.Six different types of metaatoms are presented,and the corresponding achievable wavefronts that form the holographic images in the far-field are also provided.Such a simple classification will give a straightforward approach to design and further realize advanced metasurface holographic devices.
基金supports from the National Natural Science Foundation of China(Numbers 11574240 and 11774273)the Outstanding Youth Funds of Hubei Province(Number 2016CFA034)+4 种基金the Open Foundation of State Key Laboratory of Optical Communication Technologies and Networks,Wuhan Research Institute of Posts and Telecommunications(Number OCTN-201605)the financial supports from the Postdoctoral Innovation Talent Support Program of China(BX20180221)the Global Ph.D.fellowship from the Korean government(NRF-2016H1A2A1906519)the financial support from the National Research Foundation(NRF)grants(NRF-2017R1E1A1A03070501,NRF-2017R1E1A2A01076613,NRF-2018M3D1A1058998,NRF-2015R1A5A1037668,and CAMM-2014M3A6B3063708)funded by the Ministry of Science and ICT(MSIT)of the Korean governmentthe financial support from the National Research Foundation,Prime Minister’s Office,Singapore under its Competitive Research Program(CRP award NRF CRP15-2015-03).
文摘With the rapid progress in computer science,including artificial intelligence,big data and cloud computing,full-space spot generation can be pivotal to many practical applications,such as facial recognition,motion detection,augmented reality,etc.These opportunities may be achieved by using diffractive optical elements(DOEs)or light detection and ranging(LIDAR).However,DOEs suffer from intrinsic limitations,such as demanding depth-controlled fabrication techniques,large thicknesses(more than the wavelength),Lambertian operation only in half space,etc.LIDAR nevertheless relies on complex and bulky scanning systems,which hinders the miniaturization of the spot generator.Here,inspired by a Lambertian scatterer,we report a Hermitian-conjugate metasurface scrambling the incident light to a cloud of random points in full space with compressed information density,functioning in both transmission and reflection spaces.Over 4044 random spots are experimentally observed in the entire space,covering angles at nearly 90°.Our scrambling metasurface is made of amorphous silicon with a uniform subwavelength height,a nearly continuous phase coverage,a lightweight,flexible design,and low-heat dissipation.Thus,it may be mass produced by and integrated into existing semiconductor foundry designs.Our work opens important directions for emerging 3D recognition sensors,such as motion sensing,facial recognition,and other applications.