Nonlinear frequency conversion is one of the most fundamental processes in nonlinear optics.It has a wide range of applications in our daily lives,including novel light sources,sensing,and information processing.It is...Nonlinear frequency conversion is one of the most fundamental processes in nonlinear optics.It has a wide range of applications in our daily lives,including novel light sources,sensing,and information processing.It is usually assumed that nonlinear frequency conversion requires large crystals that gradually accumulate a strong effect.However,the large size of nonlinear crystals is not compatible with the miniaturisation of modern photonic and optoelectronic systems.Therefore,shrinking the nonlinear structures down to the nanoscale,while keeping favourable conversion efficiencies,is of great importance for future photonics applications.In the last decade,researchers have studied the strategies for enhancing the nonlinear efficiencies at the nanoscale,e.g.by employing different nonlinear materials,resonant couplings and hybridization techniques.In this paper,we provide a compact review of the nanomaterials-based efforts,ranging from metal to dielectric and semiconductor nanostructures,including their relevant nanofabrication techniques.展开更多
Ten years ago,three teams experimentally demonstrated the first spasers,or plasmonic nanolasers,after the spaser concept was first proposed theoretically in 2003.An overview of the significant progress achieved over t...Ten years ago,three teams experimentally demonstrated the first spasers,or plasmonic nanolasers,after the spaser concept was first proposed theoretically in 2003.An overview of the significant progress achieved over the last 10 years is presented here,together with the original context of and motivations for this research.After a general introduction,we first summarize the fundamental properties of spasers and discuss the major motivations that led to the first demonstrations of spasers and nanolasers.This is followed by an overview of crucial technological progress,including lasing threshold reduction,dynamic modulation,room-temperature operation,electrical injection,the control and improvement of spasers,the array operation of spasers,and selected applications of single-particle spasers.Research prospects are presented in relation to several directions of development,including further miniaturization,the relationship with Bose-Einstein condensation,novel spaser-based interconnects,and other features of spasers and plasmonic lasers that have yet to be realized or challenges that are still to be overcome.展开更多
Nonlinear metasurfaces have experienced rapid growth recently due to their potential in various applications,including infrared imaging and spectroscopy.However,due to the low conversion efficiencies of metasurfaces,s...Nonlinear metasurfaces have experienced rapid growth recently due to their potential in various applications,including infrared imaging and spectroscopy.However,due to the low conversion efficiencies of metasurfaces,several strategies have been adopted to enhance their performances,including employing resonances at signal or nonlinear emission wavelengths.This strategy results in a narrow operational band of the nonlinear metasurfaces,which has bottlenecked many applications,including nonlinear holography,image encoding,and nonlinear metalenses.Here,we overcome this issue by introducing a new nonlinear imaging platform utilizing a pump beam to enhance signal conversion through four-wave mixing(FWM),whereby the metasurface is resonant at the pump wavelength rather than the signal or nonlinear emissions.As a result,we demonstrate broadband nonlinear imaging for arbitrary objects using metasurfaces.A silicon disk-on-slab metasurface is introduced with an excitable guided-mode resonance at the pump wavelength.This enabled direct conversion of a broad IR image ranging from>1000 to 4000 nm into visible.Importantly,adopting FWM substantially reduces the dependence on high-power signal inputs or resonant features at the signal beam of nonlinear imaging by utilizing the quadratic relationship between the pump beam intensity and the signal conversion efficiency.Our results,therefore,unlock the potential for broadband infrared imaging capabilities with metasurfaces,making a promising advancement for next-generation all-optical infrared imaging techniques with chip-scale photonic devices.展开更多
文摘Nonlinear frequency conversion is one of the most fundamental processes in nonlinear optics.It has a wide range of applications in our daily lives,including novel light sources,sensing,and information processing.It is usually assumed that nonlinear frequency conversion requires large crystals that gradually accumulate a strong effect.However,the large size of nonlinear crystals is not compatible with the miniaturisation of modern photonic and optoelectronic systems.Therefore,shrinking the nonlinear structures down to the nanoscale,while keeping favourable conversion efficiencies,is of great importance for future photonics applications.In the last decade,researchers have studied the strategies for enhancing the nonlinear efficiencies at the nanoscale,e.g.by employing different nonlinear materials,resonant couplings and hybridization techniques.In this paper,we provide a compact review of the nanomaterials-based efforts,ranging from metal to dielectric and semiconductor nanostructures,including their relevant nanofabrication techniques.
基金financial support from the DARPA/DSO Extreme Optics and Imaging(EXTREME)Program(Award HR00111720032)financial support from AFOSR Grant FA9550-18-1-0002+8 种基金supported by the National Natural Science Foundation of China(Grant Nos.91950115,11774014,and 61521004)the Beijing Natural Science Foundation(Grant No.Z180011)the National Key R&D Program of China(Grant No.2018YFA0704401)supported by the“UK Engineering and Physical Sciences Research Council”support from the Beijing Innovation Centre for Future Chips at Tsinghua Universityprovided by Grant No.DE-SC0007043 from the Materials Sciences and Engineering Division of the Office of the Basic Energy Sciences,Office of Science,U.S.Department of Energyperformed using support from Grant No.DE-FG02-01ER15213 from the Chemical Sciences,Biosciences and Geosciences Division,Office of Basic Energy Sciences,Office of Science,US Department of EnergyAdditional support for MIS came from NSF EFRI NewLAW Grant EFMA-1741691MURI Grant No.N00014-17-1-2588 from the Office of Naval Research(ONR).
文摘Ten years ago,three teams experimentally demonstrated the first spasers,or plasmonic nanolasers,after the spaser concept was first proposed theoretically in 2003.An overview of the significant progress achieved over the last 10 years is presented here,together with the original context of and motivations for this research.After a general introduction,we first summarize the fundamental properties of spasers and discuss the major motivations that led to the first demonstrations of spasers and nanolasers.This is followed by an overview of crucial technological progress,including lasing threshold reduction,dynamic modulation,room-temperature operation,electrical injection,the control and improvement of spasers,the array operation of spasers,and selected applications of single-particle spasers.Research prospects are presented in relation to several directions of development,including further miniaturization,the relationship with Bose-Einstein condensation,novel spaser-based interconnects,and other features of spasers and plasmonic lasers that have yet to be realized or challenges that are still to be overcome.
基金the Royal Society scholarshipG.S.acknowledges support from Biotechnology and Biological Council Doctoral Training Programme(BBSRC DTP)+1 种基金D.S.and D.N.N.acknowledge the support by the Australian Research Council(CE200100010 and FT230100058)L.Xu and M.Rahmani acknowledge support from the UK Research and Innovation Future Leaders Fellowship(MR/T040513/1)。
文摘Nonlinear metasurfaces have experienced rapid growth recently due to their potential in various applications,including infrared imaging and spectroscopy.However,due to the low conversion efficiencies of metasurfaces,several strategies have been adopted to enhance their performances,including employing resonances at signal or nonlinear emission wavelengths.This strategy results in a narrow operational band of the nonlinear metasurfaces,which has bottlenecked many applications,including nonlinear holography,image encoding,and nonlinear metalenses.Here,we overcome this issue by introducing a new nonlinear imaging platform utilizing a pump beam to enhance signal conversion through four-wave mixing(FWM),whereby the metasurface is resonant at the pump wavelength rather than the signal or nonlinear emissions.As a result,we demonstrate broadband nonlinear imaging for arbitrary objects using metasurfaces.A silicon disk-on-slab metasurface is introduced with an excitable guided-mode resonance at the pump wavelength.This enabled direct conversion of a broad IR image ranging from>1000 to 4000 nm into visible.Importantly,adopting FWM substantially reduces the dependence on high-power signal inputs or resonant features at the signal beam of nonlinear imaging by utilizing the quadratic relationship between the pump beam intensity and the signal conversion efficiency.Our results,therefore,unlock the potential for broadband infrared imaging capabilities with metasurfaces,making a promising advancement for next-generation all-optical infrared imaging techniques with chip-scale photonic devices.
