In the present work,a wavelength-selected plasma imaging analysis system is presented and used to track photons emitted from single-trapped nanoparticles in air at atmospheric pressure.The isolated nanoentities were a...In the present work,a wavelength-selected plasma imaging analysis system is presented and used to track photons emitted from single-trapped nanoparticles in air at atmospheric pressure.The isolated nanoentities were atomized and excited into plasma state using single nanosecond laser pulses.The use of appropriate wavelength filters alongside time-optimized acquisition settings enabled the detection of molecular and atomic emissions in the plasma.The photon detection efficiency of the imaging line resulted in a signal>400 times larger than the simultaneously-acquired dispersive spectroscopy data.The increase in sensitivity outlined the evolution of diverse physicochemical processes at the single particle scale which included heat and momentum transfer from the plasma into the particle as wells as chemical reactions.The imaging detection of excited fragments evidenced different diffusion kinetics and time frames for atoms and molecules and their influence upon both the spectroscopic emission readout and fabrication processes using the plasma as a reactor.Moreover,the origin of molecular species,whether naturally-occurring or derived from a chemical reaction in the plasma,could also be studied on the basis of compositional gradients found on the images.Limits of detection for the inspected species ranged from tens to hundreds attograms,thus leading to an exceptional sensing principle for single nanoentities that may impact several areas of science and technology.展开更多
A flexible-grid 1×(2×3)mode-and wavelength-selective switch which comprises counter-tapered couplers and silicon microring resonators has been proposed,optimized,and demonstrated experimentally in this work....A flexible-grid 1×(2×3)mode-and wavelength-selective switch which comprises counter-tapered couplers and silicon microring resonators has been proposed,optimized,and demonstrated experimentally in this work.By carefully thermally tuning phase shifters and silicon microring resonators,mode and wavelength signals can be independently and flexibly conveyed to any one of the output ports,and different bandwidths can be generated as desired.The particle swarm optimization algorithm and finite difference time-domain method are employed to optimize structural parameters of the twomode(de)multiplexer and crossing waveguide.The bandwidth-tunable wavelength-selective optical router composed of12 microring resonators is studied by taking advantage of the transfer matrix method.Measurement results show that,for the fabricated module,cross talk less than-10.18 dB,an extinction ratio larger than 17.41 d B,an in-band ripple lower than0.79 dB,and a 3-dB bandwidth changing from 0.38 to 1.05 nm are obtained,as the wavelength-channel spacing is 0.40 nm.The corresponding response time is measured to be 13.64μs.展开更多
Space-division multiplexing （SDM） using multi-core fibers （MCFs） and few-mode fibers （FMFs） was proposed as a solution to increase capacity and/or reduce the cost per bit of fiber-optic transmission. Advances in...Space-division multiplexing （SDM） using multi-core fibers （MCFs） and few-mode fibers （FMFs） was proposed as a solution to increase capacity and/or reduce the cost per bit of fiber-optic transmission. Advances in passive and active SDM devices as well as digital signal processing have led to impressive SDM transmission demonstrations in the laboratory. Although the perceived advantages in terms of capacity and cost per bit that SDM offers over parallel SMF bundles are not universally accepted, SDM is beginning to emerge as an indispensable solution in major network segments. The introduction of the spatial degree of freedom allows optical networks to overcome fundamental limitations such as fiber nonlinearity as well practical limitations such as power delivery. We describe these application scenarios that the optical communications industry has already began to explore. From a fundamental science point of view, concepts such as the principal modes, generalized Stokes space, and multi-component solitons discovered in SDM research will likely have a broad impact in other areas of science and engineering.展开更多
The manipulation of the polarization properties of light in guided media is crucial in many classical and quantum optical systems.However,the capability of current technology to finely define the state of polarization...The manipulation of the polarization properties of light in guided media is crucial in many classical and quantum optical systems.However,the capability of current technology to finely define the state of polarization of particular wavelengths is far from the level of maturity in amplitude control.Here,we introduce a light-by-light polarization control mechanism with wavelength selectivity based on the change of the phase retardance by means of stimulated Brillouin scattering.Experiments show that any point on the Poincare sphere can be reached from an arbitrary input state of polarization with little variation of the signal amplitude(<2.5 dB).Unlike other Brillouin processing schemes,the degradation of the noise figure is small(1.5 dB for a full 2πrotation).This all-optical polarization controller can forge the development of new polarization-based techniques in optical communication,laser engineering,sensing,quantum systems,and light-based probing of chemical and biological systems.展开更多
A theoretical design is presented for a 1 × M wavelength-selective switch(WSS) that routes any one of N incoming wavelength signals to any one of M output ports. This planar on-chip device comprises of a 1 ×...A theoretical design is presented for a 1 × M wavelength-selective switch(WSS) that routes any one of N incoming wavelength signals to any one of M output ports. This planar on-chip device comprises of a 1 × N demultiplexer, a group of N switching "trees" actuated by electro-optical or thermo-optical means, and an M-fold set of N × 1multiplexers. Trees utilize 1 × 2 switches. The WSS insertion loss is proportional to [log_2(M+N +1)]. Along with cross talk from trees, cross talk is present at each cross-illuminated waveguide intersection within the WSS, and there are at most N-1 such crossings per path. These loss and cross talk properties will likely place a practical limit of N=M=16 upon the WSS size. By constraining the 1 × 2 switching energy to^1 f J∕bit, we find that resonant, narrowband 1 × 2 switches are required. The 1 × 2 devices proposed here are nanobeam Mach–Zehnders and asymmetric contra-directional couplers with grating assistance.展开更多
This paper discusses a 40-Gbit/s transparent optical network focusing on the optical transport performance. We show 1200-km transmission with two WSOXC' sspaced by 400 km. In addition, network control issues are b...This paper discusses a 40-Gbit/s transparent optical network focusing on the optical transport performance. We show 1200-km transmission with two WSOXC' sspaced by 400 km. In addition, network control issues are briefly addressed.展开更多
基金the Spanish Ministerio de Economia y Competitividad(Nos.CTQ2017-82137P and CTQ2014-56058P).
文摘In the present work,a wavelength-selected plasma imaging analysis system is presented and used to track photons emitted from single-trapped nanoparticles in air at atmospheric pressure.The isolated nanoentities were atomized and excited into plasma state using single nanosecond laser pulses.The use of appropriate wavelength filters alongside time-optimized acquisition settings enabled the detection of molecular and atomic emissions in the plasma.The photon detection efficiency of the imaging line resulted in a signal>400 times larger than the simultaneously-acquired dispersive spectroscopy data.The increase in sensitivity outlined the evolution of diverse physicochemical processes at the single particle scale which included heat and momentum transfer from the plasma into the particle as wells as chemical reactions.The imaging detection of excited fragments evidenced different diffusion kinetics and time frames for atoms and molecules and their influence upon both the spectroscopic emission readout and fabrication processes using the plasma as a reactor.Moreover,the origin of molecular species,whether naturally-occurring or derived from a chemical reaction in the plasma,could also be studied on the basis of compositional gradients found on the images.Limits of detection for the inspected species ranged from tens to hundreds attograms,thus leading to an exceptional sensing principle for single nanoentities that may impact several areas of science and technology.
基金supported by the National Natural Science Foundation of China(Nos.62275134,62234008,61875098,and 61874078)the Zhejiang Provincial Natural Science Foundation(Nos.LY20F050003 and LY20F050001)+2 种基金the Natural Science Foundation of Ningbo(Nos.2022J099 and 202003N4159)the Youth Science and Technology Innovation Leading Talent Project of Ningbo(No.2023QL003)the K.C.Wong Magna Fund at Ningbo University。
文摘A flexible-grid 1×(2×3)mode-and wavelength-selective switch which comprises counter-tapered couplers and silicon microring resonators has been proposed,optimized,and demonstrated experimentally in this work.By carefully thermally tuning phase shifters and silicon microring resonators,mode and wavelength signals can be independently and flexibly conveyed to any one of the output ports,and different bandwidths can be generated as desired.The particle swarm optimization algorithm and finite difference time-domain method are employed to optimize structural parameters of the twomode(de)multiplexer and crossing waveguide.The bandwidth-tunable wavelength-selective optical router composed of12 microring resonators is studied by taking advantage of the transfer matrix method.Measurement results show that,for the fabricated module,cross talk less than-10.18 dB,an extinction ratio larger than 17.41 d B,an in-band ripple lower than0.79 dB,and a 3-dB bandwidth changing from 0.38 to 1.05 nm are obtained,as the wavelength-channel spacing is 0.40 nm.The corresponding response time is measured to be 13.64μs.
基金This work has been supported in part by the National Basic Research Program of China （973） （No. 2014CB340104/1）, the National Natural Science Foundation of China （NSFC） （Grant Nos. 61377076, 61307085 and 61431009）.
文摘Space-division multiplexing （SDM） using multi-core fibers （MCFs） and few-mode fibers （FMFs） was proposed as a solution to increase capacity and/or reduce the cost per bit of fiber-optic transmission. Advances in passive and active SDM devices as well as digital signal processing have led to impressive SDM transmission demonstrations in the laboratory. Although the perceived advantages in terms of capacity and cost per bit that SDM offers over parallel SMF bundles are not universally accepted, SDM is beginning to emerge as an indispensable solution in major network segments. The introduction of the spatial degree of freedom allows optical networks to overcome fundamental limitations such as fiber nonlinearity as well practical limitations such as power delivery. We describe these application scenarios that the optical communications industry has already began to explore. From a fundamental science point of view, concepts such as the principal modes, generalized Stokes space, and multi-component solitons discovered in SDM research will likely have a broad impact in other areas of science and engineering.
基金Ministerio de Ciencia,Innovación y Universidades(TEC2016-80906-R)。
文摘The manipulation of the polarization properties of light in guided media is crucial in many classical and quantum optical systems.However,the capability of current technology to finely define the state of polarization of particular wavelengths is far from the level of maturity in amplitude control.Here,we introduce a light-by-light polarization control mechanism with wavelength selectivity based on the change of the phase retardance by means of stimulated Brillouin scattering.Experiments show that any point on the Poincare sphere can be reached from an arbitrary input state of polarization with little variation of the signal amplitude(<2.5 dB).Unlike other Brillouin processing schemes,the degradation of the noise figure is small(1.5 dB for a full 2πrotation).This all-optical polarization controller can forge the development of new polarization-based techniques in optical communication,laser engineering,sensing,quantum systems,and light-based probing of chemical and biological systems.
基金Air Force Office of Scientific Research(AFOSR)(FA9550-14-1-0196)
文摘A theoretical design is presented for a 1 × M wavelength-selective switch(WSS) that routes any one of N incoming wavelength signals to any one of M output ports. This planar on-chip device comprises of a 1 × N demultiplexer, a group of N switching "trees" actuated by electro-optical or thermo-optical means, and an M-fold set of N × 1multiplexers. Trees utilize 1 × 2 switches. The WSS insertion loss is proportional to [log_2(M+N +1)]. Along with cross talk from trees, cross talk is present at each cross-illuminated waveguide intersection within the WSS, and there are at most N-1 such crossings per path. These loss and cross talk properties will likely place a practical limit of N=M=16 upon the WSS size. By constraining the 1 × 2 switching energy to^1 f J∕bit, we find that resonant, narrowband 1 × 2 switches are required. The 1 × 2 devices proposed here are nanobeam Mach–Zehnders and asymmetric contra-directional couplers with grating assistance.
文摘This paper discusses a 40-Gbit/s transparent optical network focusing on the optical transport performance. We show 1200-km transmission with two WSOXC' sspaced by 400 km. In addition, network control issues are briefly addressed.
