The dynamic response of molecular orientation, and the temperature and pulse shape dependences of the switching behavior in ferroelectric liquid crystal are described. The switching speed and the surface energy of fer...The dynamic response of molecular orientation, and the temperature and pulse shape dependences of the switching behavior in ferroelectric liquid crystal are described. The switching speed and the surface energy of ferroelectric liquid crystal are given.展开更多
Applications of optical switches,such as signal routing and data-intensive computing,are critical in optical interconnects and optical computing.Integrated optical switches enabled by two-dimensional(2D)materials and ...Applications of optical switches,such as signal routing and data-intensive computing,are critical in optical interconnects and optical computing.Integrated optical switches enabled by two-dimensional(2D)materials and beyond,such as graphene and black phosphorus,have demonstrated many advantages in terms of speed and energy consumption compared to their conventional silicon-based counterparts.Here we review the state-of-the-art of optical switches enabled by 2D materials and beyond and organize them into several tables.The performance tables and future projections show the frontiers of optical switches fabricated from 2D materials and beyond,providing researchers with an overview of this field and enabling them to identify existing challenges and predict promising research directions.展开更多
Utilizing optical technologies for the design of packet switches and routers offers several advantages in terms of scalability, high bandwidth, power consumption, and cost. However, the configuration delays of optical...Utilizing optical technologies for the design of packet switches and routers offers several advantages in terms of scalability, high bandwidth, power consumption, and cost. However, the configuration delays of optical crossbars are much longer than that of the electronic counterpart, which makes the conventional slot-by-slot scheduling methods no longer the feasible solution. Therefore, some tradeoff must be found between the empty time slots and configuration overhead. This paper classifies such scheduling problems into preemptive and non-preemptive scenarios, each has its own advantages and disadvantages. Although non-preemptive scheduling is inherently not good at achieving the above-mentioned tradeoff, it is shown, however, that the proposed maximum weight matching (MWM) based greedy algorithm is guaranteed to achieve an approximation 2 for arbitrary configuration delay, and with a relatively low time complexity O(N^2). For preemptive scheduling, a novel 2-approximation heuristic is presented. Each time in finding a switch configuration, the 2-approximation heuristic guarantees the covering cost of the remaining traffic matrix to have 2-approximation. Simulation results demonstrate that 2-approximation heuristic (1) performs close to the optimal scheduling, and (2) outperforms ADJUST and DOUBLE in terms of traffic transmission delay and time complexity.展开更多
A micromechanical optical switch driven by electrostatic was fabricated with (100) silicon and tilted 2.5° (111) silicon. The pull-in voltage is 13.2V, the insertion loss is less than 1.4dB, the crosstalk is less...A micromechanical optical switch driven by electrostatic was fabricated with (100) silicon and tilted 2.5° (111) silicon. The pull-in voltage is 13.2V, the insertion loss is less than 1.4dB, the crosstalk is less than -50 dB.展开更多
Optical time division multiplexing (OTDM) is one of the promisinig ways for the future high speed optical fiber communication networks. All optical switch is, being one of the core technologies of OTDM systems and n...Optical time division multiplexing (OTDM) is one of the promisinig ways for the future high speed optical fiber communication networks. All optical switch is, being one of the core technologies of OTDM systems and networks, crucial to realize the various signal processes including time division demultiplexing, packet switching, all optical regenerating and so on. This thesis mainly studies various all optical switch technologies and their utilization in the fields of all optical signal processings in the OTDM systems and networks. The main jobs are listed as follows.\; (1) A novel all optical ultrafast demultiplexing scheme using the soliton self trapping effect in birefringent fiber is proposed.\; (2) The demultiplexing performance of the Nonlinear Optical Loop Mirror(NOLM) is thoroughly analyzed and its optimization is further discussed.\; (3) The performance analysis and the configuration optimization of the all optical switches based on the Semiconductor Optical Amplifier(SOA) are systematically presented. The speed limitation of the all optical SOA switches induced by the fast gain depletion of SOA is discussed. Besides, a novel SOA switch is proposed, which adopts the asymmetric Mach Zehnder Interferometer configuration.\; (4) The 8×2\^5 Gb/s OTDM experimental transmission system along 105 km standard fiber is realized using the NOLM demultiplexer.\; (5) The NOLM switch is used to realize the all optical 3R regeneration of 2\^5 Gb/s Return to Zero signal.\; (6) The feasibility and limitation of the all optical SOA packet switch is discussed. And a developed MZI configuration of SOA packet switch is further shown to improve the packet switching performance. Finally, an all optical packet dropping node suitable in the networks with ring or bus configuration and an all optical packet switching node in the ShuffleNet networks are proposed to show the feasibility of all optical packet switching through combining the all optical switches and the reasonable logic decisions.展开更多
Silicon photonic devices consisting of nanowire waveguides are a promising technology for on-chip integration in future optical telecommunication and interconnection systems based on silicon-large scale integration fa...Silicon photonic devices consisting of nanowire waveguides are a promising technology for on-chip integration in future optical telecommunication and interconnection systems based on silicon-large scale integration fabrication.However,the accommodation of variable optical components on a chip remains challenging due to the small size of microchips.In this study,we investigated the characteristics of a microelectromechanical silicon nanowire waveguide switch with a gap-variable coupler.Due to its capacitive operation,the proposed waveguide switch consumed negligible power relative to switches that use a thermo-optical effect and carrier injection.The proposed switch was characterized using analyses based on coupled-mode theory for rectangular waveguides,as well as a simulation using the finite difference time domain method.A 2×2 single switch with an improved configuration and a 2×6 multiple switch composed of the 2×2 switches was designed and fabricated by a combination of electron beam lithography,fast-atom beam etching and hydrofluoric acid vapor sacrificial etching.The properties of the switches were measured and evaluated at a wavelength of 1.55 μm.展开更多
Micro-optical electromechanical systems(MOEMS)combine the merits of micro-electromechanical systems(MEMS)and micro-optics to enable unique optical functions for a wide range of advanced applications.Using simple exter...Micro-optical electromechanical systems(MOEMS)combine the merits of micro-electromechanical systems(MEMS)and micro-optics to enable unique optical functions for a wide range of advanced applications.Using simple external electromechanical control methods,such as electrostatic,magnetic or thermal effects,Si-based MOEMS can achieve precise dynamic optical modulation.In this paper,we will briefly review the technologies and applications of Si-based MOEMS.Their basic working principles,advantages,general materials and micromachining fabrication technologies are introduced concisely,followed by research progress of advanced Si-based MOEMS devices,including micromirrors/micromirror arrays,micro-spectrometers,and optical/photonic switches.Owing to the unique advantages of Si-based MOEMS in spatial light modulation and high-speed signal processing,they have several promising applications in optical communications,digital light processing,and optical sensing.Finally,future research and development prospects of Si-based MOEMS are discussed.展开更多
A multifunctional surface plasmon polariton disk device coupled by two metal-insulator-metal(MIM) waveguides is proposed and investigated numerically with finite-difference time-domain simulation. It can be used as ...A multifunctional surface plasmon polariton disk device coupled by two metal-insulator-metal(MIM) waveguides is proposed and investigated numerically with finite-difference time-domain simulation. It can be used as optical switch and temperature sensor by filling disk with liquid crystal and ethanol, respectively. The simulation results demonstrate that the transmission characteristics of an optical switch can be manipulated by adjusting the radius of disk and the slit width between disk and MIM waveguides. The transmittance and modulation depth of optical switch at 1550 nm are up to 64.82% and 17.70 d B, respectively. As a temperature sensor, its figure of merit can reach 30.46. In this paper, an optical switch with better efficiency and a temperature sensor with better sensitivity can be achieved.展开更多
We experimentally demonstrate a small-size and high-speed silicon optical switch based on the free carrier plasma dispersion in silicon. Using an embedded racetrack resonator with a quality factor of 7400, the optical...We experimentally demonstrate a small-size and high-speed silicon optical switch based on the free carrier plasma dispersion in silicon. Using an embedded racetrack resonator with a quality factor of 7400, the optical switch shows an extinction ratio exceeding 13 dB with a footprint of only 2.2 × 10-3 mm^2. Moreover, a novel pre-emphasis technique is introduced to improve the optical response performance and the rise and the fall times are reduced down to 0.24 ns and 0.42 ns respectively, which are 25% and 44% lower than those without the pre-emphasis.展开更多
Optical nanofiber(ONF)is a special tool to achieve the interaction between light and matter with ultralow power.In this paper,we demonstrate V-type electromagnetically induced transparency(EIT)in cold atoms trapped by...Optical nanofiber(ONF)is a special tool to achieve the interaction between light and matter with ultralow power.In this paper,we demonstrate V-type electromagnetically induced transparency(EIT)in cold atoms trapped by an ONFbased two-color optical lattice.At an optical depth of 7.35,90%transmission can be achieved by only 7.7 pW coupling power.The EIT peak and linewidth are investigated as a function of the coupling optical power.By modulating the pWlevel control beam of the ONF-EIT system in sequence,we further achieve efficient and high contrast control of the probe transmission,as well as its potential application in the field of quantum communication and quantum information science by using one-dimensional atomic chains.展开更多
The transmission characteristics of the optical label switching system based on the FSK/ASK orthogonal modulation format is investigated. The factors that affect the transmission performance, such as the FSK tone spac...The transmission characteristics of the optical label switching system based on the FSK/ASK orthogonal modulation format is investigated. The factors that affect the transmission performance, such as the FSK tone space, dispersion compensation and coupler split ratio, are studied by numerical simulation. The proposed scheme is also experimentally demonstrated with a transmission of 155 Mbit/s FSK label combined with 10 Gbit/s ASK payload.展开更多
In order to apply compressive sensing in wireless sensor network, inside the nodes cluster classified by the spatial correlation, we propose that a cluster head adopts free space optical communication with space divis...In order to apply compressive sensing in wireless sensor network, inside the nodes cluster classified by the spatial correlation, we propose that a cluster head adopts free space optical communication with space division multiple access, and a sensor node uses a modulating retro-reflector for communication. Thus while a random sampling matrix is used to guide the establishment of links between head cluster and sensor nodes, the random linear projection is accomplished. To establish multiple links at the same time, an optical space division multiple access antenna is designed. It works in fixed beams switching mode and consists of optic lens with a large field of view(FOV), fiber array on the focal plane which is used to realize virtual channels segmentation, direction of arrival sensor, optical matrix switch and controller. Based on the angles of nodes' laser beams, by dynamically changing the route, optical matrix switch actualizes the multi-beam full duplex tracking receiving and transmission. Due to the structure of fiber array, there will be several fade zones both in the focal plane and in lens' FOV. In order to lower the impact of fade zones and harmonize multibeam, a fiber array adjustment is designed. By theoretical, simulated and experimental study, the antenna's qualitative feasibility is validated.展开更多
Application of the pressure controlled isothermal heating vertical deposition method to the fabrication of colloidal photonic crystals is systematically investigated in this paper. The fabricated samples are character...Application of the pressure controlled isothermal heating vertical deposition method to the fabrication of colloidal photonic crystals is systematically investigated in this paper. The fabricated samples are characterized by scanning electron microscope and transmission spectrum. High-quality samples with large transmissions in the pass bands and the sharp band edges are obtained and the optimum growth condition is determined. For the best sample, the transmission in the pass bands approaches 0.9 while that in the band gap reaches 0.1. More importantly, the maximum differential transmission as high as 0.1/nm is achieved. In addition, it is found that the number of stacking layers does not increase linearly with concentration of PS spheres in a solution, and a gradual saturation occurs when the concentration of PS spheres exceeds 1.5 wt.%. The uniformity of the fabricated samples is examined by transmission measurements on areas with different sizes. Finally, the tolerance of the fabricated samples to baking was studied.展开更多
Optical switch fabric plays an important role in building multiple-user optical quantum communication networks.Owing to its self-routing property and low complexity, a banyan network is widely used for building switch...Optical switch fabric plays an important role in building multiple-user optical quantum communication networks.Owing to its self-routing property and low complexity, a banyan network is widely used for building switch fabric. While,there is no efficient way to remove internal blocking in a banyan network in a classical way, quantum state fusion, by which the two-dimensional internal quantum states of two photons could be combined into a four-dimensional internal state of a single photon, makes it possible to solve this problem. In this paper, we convert the output mode of quantum state fusion from spatial-polarization mode into time-polarization mode. By combining modified quantum state fusion and quantum state fission with quantum Fredkin gate, we propose a practical scheme to build an optical quantum switch unit which is block free. The scheme can be extended to building more complex units, four of which are shown in this paper.展开更多
We report a strict non-blocking four-port optical router that is used for a mesh photonic network-on-chip on a silicon-on-insulator platform.The router consists of eight silicon microring switches that are tuned by th...We report a strict non-blocking four-port optical router that is used for a mesh photonic network-on-chip on a silicon-on-insulator platform.The router consists of eight silicon microring switches that are tuned by the thermo-optic effect.For each tested rousting state,the signal-to-noise ratio of the optical router is larger than 13.8 dB at the working wavelength.The routing functionality of the device is verified.We perform 40 Gbps nonreturn to zero code data transmission on its 12 optical links.Meanwhile,data transmission using wavelength division multiplexing on eight channels in the C band(from 1525 to 1565 nm)has been adopted to increase the communication capacity.The optical router’s average energy efficiency is 25.52 fJ/bit.The rising times(10%to 90%)of the eight optical switch elements are less than 10μs and the falling times(90%-10%)are less than 20μs.展开更多
This paper demonstrates the realization of an optical switch by optically manipulating a large number of polystyrene spheres contained in a capillary. The strong scattering force exerted on polystyrene spheres with a ...This paper demonstrates the realization of an optical switch by optically manipulating a large number of polystyrene spheres contained in a capillary. The strong scattering force exerted on polystyrene spheres with a large diameter of 4.3 μm is employed to realize the switching operation. A transparent window is opened for the signal light when the polystyrene spheres originally located at the beam centre are driven out of the beam region by the strong scattering force induced by the control light. The switching dynamics under different incident powers is investigated and compared with that observed in the optical switch based on the formation of optical matter. It is found that a large extinction ratio of - 30 dB and fast switching-on and switching-off times can be achieved in this type of switch.展开更多
To promote the future quantum information technologies, we demonstrate an electrically driven optical switch based on quantum interference in a hybrid opto-electromechanical system, which consists of an opto-mechanica...To promote the future quantum information technologies, we demonstrate an electrically driven optical switch based on quantum interference in a hybrid opto-electromechanical system, which consists of an opto-mechanical cavity and an external electric circuit. The key element of our scheme is a moveable mirror of cavity as a charged mechanical oscillator capacitively coupled to a fixed charged plate in a variable capacitor. By adjusting the voltage of the capacitor, the displacement of the moveable mirror is modulated, then the cavity field can be electrically turned on or off due to the detuning of the cavity. Based on the cavity induced transparency, the transparency window can be electrically switched on or off by turning on or off the cavity field. Therefore, the susceptibility of the medium in the cavity can be electrically controlled, i.e., the scheme of the electrically controlled absorption switching can be demonstrated. This electrically driven optical switch will excite a development trend and implementation prospect towards the integration and miniaturization of quantum module device in a chip.展开更多
The effect of queuing delay of output buffer on the crosstalk property in optical packet switching nodes is investigated. The relationship between crosstalk and buffer length is obtained. From the calculation and simu...The effect of queuing delay of output buffer on the crosstalk property in optical packet switching nodes is investigated. The relationship between crosstalk and buffer length is obtained. From the calculation and simulation results, it is concluded that the crosstalk power penalty predominantly depends on the buffer length, the longer the buffer, the greater the penalty, as well as the random range of the penalty. While comparing with the effect of queuing delay, the effect of random routing path delay takes very little proportion in the total power penalty.展开更多
We investigate the nonlinear dynamics of a system composed of a cigar-shaped Bose-Einstein condensate and an optical cavity with the two sides coupled dispersively.By adopting discrete-mode approximation for the conde...We investigate the nonlinear dynamics of a system composed of a cigar-shaped Bose-Einstein condensate and an optical cavity with the two sides coupled dispersively.By adopting discrete-mode approximation for the condensate,taking atom loss as a necessary part of the model to analyze the evolution of the system,while using trial and error method to find out steady states of the system as a reference,numerical simulation demonstrates that with a constant pump,atom loss will trigger a quantum optical bi-stability switch,which predicts a new interesting phenomenon for experiments to verify.展开更多
This paper introduces the mid-span spectral inversion by four-wave mixing in a commercially available semiconductor optical amplifier (SOA) with a length of about 1.5 mm to optical label switching network based on c...This paper introduces the mid-span spectral inversion by four-wave mixing in a commercially available semiconductor optical amplifier (SOA) with a length of about 1.5 mm to optical label switching network based on combined frequency shift keying (FSK)-intensiy modulation (IM)/optical label-packet modulation to overcome the dispersion limitation of fiber. The 155 Mb/s-10 Gb/s combined FSK/IM signal is experimentally transmitted over a 100 km standard single mode fiber. 10^-10 and 10^-9 BER (bit error ratio), or even better, is achieved for the FSK label and IM packet, respectively. The -19 dB power conversion efficiency is obtained for -1 nm wavelength detuning.展开更多
文摘The dynamic response of molecular orientation, and the temperature and pulse shape dependences of the switching behavior in ferroelectric liquid crystal are described. The switching speed and the surface energy of ferroelectric liquid crystal are given.
基金supported in part by the National Key Research and Development Project of China(No.2018YFB2201901)in part by the National Natural Science Foundation of China(Grant No.61805090).
文摘Applications of optical switches,such as signal routing and data-intensive computing,are critical in optical interconnects and optical computing.Integrated optical switches enabled by two-dimensional(2D)materials and beyond,such as graphene and black phosphorus,have demonstrated many advantages in terms of speed and energy consumption compared to their conventional silicon-based counterparts.Here we review the state-of-the-art of optical switches enabled by 2D materials and beyond and organize them into several tables.The performance tables and future projections show the frontiers of optical switches fabricated from 2D materials and beyond,providing researchers with an overview of this field and enabling them to identify existing challenges and predict promising research directions.
文摘Utilizing optical technologies for the design of packet switches and routers offers several advantages in terms of scalability, high bandwidth, power consumption, and cost. However, the configuration delays of optical crossbars are much longer than that of the electronic counterpart, which makes the conventional slot-by-slot scheduling methods no longer the feasible solution. Therefore, some tradeoff must be found between the empty time slots and configuration overhead. This paper classifies such scheduling problems into preemptive and non-preemptive scenarios, each has its own advantages and disadvantages. Although non-preemptive scheduling is inherently not good at achieving the above-mentioned tradeoff, it is shown, however, that the proposed maximum weight matching (MWM) based greedy algorithm is guaranteed to achieve an approximation 2 for arbitrary configuration delay, and with a relatively low time complexity O(N^2). For preemptive scheduling, a novel 2-approximation heuristic is presented. Each time in finding a switch configuration, the 2-approximation heuristic guarantees the covering cost of the remaining traffic matrix to have 2-approximation. Simulation results demonstrate that 2-approximation heuristic (1) performs close to the optimal scheduling, and (2) outperforms ADJUST and DOUBLE in terms of traffic transmission delay and time complexity.
文摘A micromechanical optical switch driven by electrostatic was fabricated with (100) silicon and tilted 2.5° (111) silicon. The pull-in voltage is 13.2V, the insertion loss is less than 1.4dB, the crosstalk is less than -50 dB.
文摘Optical time division multiplexing (OTDM) is one of the promisinig ways for the future high speed optical fiber communication networks. All optical switch is, being one of the core technologies of OTDM systems and networks, crucial to realize the various signal processes including time division demultiplexing, packet switching, all optical regenerating and so on. This thesis mainly studies various all optical switch technologies and their utilization in the fields of all optical signal processings in the OTDM systems and networks. The main jobs are listed as follows.\; (1) A novel all optical ultrafast demultiplexing scheme using the soliton self trapping effect in birefringent fiber is proposed.\; (2) The demultiplexing performance of the Nonlinear Optical Loop Mirror(NOLM) is thoroughly analyzed and its optimization is further discussed.\; (3) The performance analysis and the configuration optimization of the all optical switches based on the Semiconductor Optical Amplifier(SOA) are systematically presented. The speed limitation of the all optical SOA switches induced by the fast gain depletion of SOA is discussed. Besides, a novel SOA switch is proposed, which adopts the asymmetric Mach Zehnder Interferometer configuration.\; (4) The 8×2\^5 Gb/s OTDM experimental transmission system along 105 km standard fiber is realized using the NOLM demultiplexer.\; (5) The NOLM switch is used to realize the all optical 3R regeneration of 2\^5 Gb/s Return to Zero signal.\; (6) The feasibility and limitation of the all optical SOA packet switch is discussed. And a developed MZI configuration of SOA packet switch is further shown to improve the packet switching performance. Finally, an all optical packet dropping node suitable in the networks with ring or bus configuration and an all optical packet switching node in the ShuffleNet networks are proposed to show the feasibility of all optical packet switching through combining the all optical switches and the reasonable logic decisions.
文摘Silicon photonic devices consisting of nanowire waveguides are a promising technology for on-chip integration in future optical telecommunication and interconnection systems based on silicon-large scale integration fabrication.However,the accommodation of variable optical components on a chip remains challenging due to the small size of microchips.In this study,we investigated the characteristics of a microelectromechanical silicon nanowire waveguide switch with a gap-variable coupler.Due to its capacitive operation,the proposed waveguide switch consumed negligible power relative to switches that use a thermo-optical effect and carrier injection.The proposed switch was characterized using analyses based on coupled-mode theory for rectangular waveguides,as well as a simulation using the finite difference time domain method.A 2×2 single switch with an improved configuration and a 2×6 multiple switch composed of the 2×2 switches was designed and fabricated by a combination of electron beam lithography,fast-atom beam etching and hydrofluoric acid vapor sacrificial etching.The properties of the switches were measured and evaluated at a wavelength of 1.55 μm.
基金supported by the National Natural Science Foundation of China under Grant No.61975016the Science and Technology Project of Guangdong(2020B010190001)+2 种基金Natural Science Foundation of Beijing Municipality(1212013 and Z190006)Beijing Municipal Science&Technology Commission,Administrative Commission of Zhongguancun Science Park No.Z211100004821009Cultivation Project for Basic Research and Innovation of Yanshan University No.2021LGQN021.
文摘Micro-optical electromechanical systems(MOEMS)combine the merits of micro-electromechanical systems(MEMS)and micro-optics to enable unique optical functions for a wide range of advanced applications.Using simple external electromechanical control methods,such as electrostatic,magnetic or thermal effects,Si-based MOEMS can achieve precise dynamic optical modulation.In this paper,we will briefly review the technologies and applications of Si-based MOEMS.Their basic working principles,advantages,general materials and micromachining fabrication technologies are introduced concisely,followed by research progress of advanced Si-based MOEMS devices,including micromirrors/micromirror arrays,micro-spectrometers,and optical/photonic switches.Owing to the unique advantages of Si-based MOEMS in spatial light modulation and high-speed signal processing,they have several promising applications in optical communications,digital light processing,and optical sensing.Finally,future research and development prospects of Si-based MOEMS are discussed.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61275059 and 61307062)
文摘A multifunctional surface plasmon polariton disk device coupled by two metal-insulator-metal(MIM) waveguides is proposed and investigated numerically with finite-difference time-domain simulation. It can be used as optical switch and temperature sensor by filling disk with liquid crystal and ethanol, respectively. The simulation results demonstrate that the transmission characteristics of an optical switch can be manipulated by adjusting the radius of disk and the slit width between disk and MIM waveguides. The transmittance and modulation depth of optical switch at 1550 nm are up to 64.82% and 17.70 d B, respectively. As a temperature sensor, its figure of merit can reach 30.46. In this paper, an optical switch with better efficiency and a temperature sensor with better sensitivity can be achieved.
基金Project supported by the National Natural Science Foundation of China(Grant No.60877036)the National Basic Research Program of China(Grant No.2006CB302803)+1 种基金the State Key Laboratory of Advanced Optical Communication Systems and Networks,China(Grant No.2008SH02)the Knowledge Innovation Program of Institute of Semiconductors,Chinese Academy of Sciences(Grant No.ISCAS2008T10)
文摘We experimentally demonstrate a small-size and high-speed silicon optical switch based on the free carrier plasma dispersion in silicon. Using an embedded racetrack resonator with a quality factor of 7400, the optical switch shows an extinction ratio exceeding 13 dB with a footprint of only 2.2 × 10-3 mm^2. Moreover, a novel pre-emphasis technique is introduced to improve the optical response performance and the rise and the fall times are reduced down to 0.24 ns and 0.42 ns respectively, which are 25% and 44% lower than those without the pre-emphasis.
基金supported by State Grid science and Technology Project(Grant No.5700-202127198A-0-0-00)。
文摘Optical nanofiber(ONF)is a special tool to achieve the interaction between light and matter with ultralow power.In this paper,we demonstrate V-type electromagnetically induced transparency(EIT)in cold atoms trapped by an ONFbased two-color optical lattice.At an optical depth of 7.35,90%transmission can be achieved by only 7.7 pW coupling power.The EIT peak and linewidth are investigated as a function of the coupling optical power.By modulating the pWlevel control beam of the ONF-EIT system in sequence,we further achieve efficient and high contrast control of the probe transmission,as well as its potential application in the field of quantum communication and quantum information science by using one-dimensional atomic chains.
基金supported by the National Natural Science Foundation of China(Grant No 60677004)the National High Technology Research and Development Program of China(Grant No 2007AA01Z260)+4 种基金The project is also supported by the Key Project of Chinese Ministry of Education(Grant No 107011)the Key Laboratory of Broadband Optical Fiber Transmission and Communication Networks(UESTC)(Ministry of Education of China)Teaching and Scientific Research Foundation for the Returned Overseas Chinese Scholars(State Education Ministry of China)the Corporative Building Project of Beijing Educational Committee(Grant No XK100130737)the Program for New Century Excellent Talents in University of China(Grant No NECT-07-0111)
文摘The transmission characteristics of the optical label switching system based on the FSK/ASK orthogonal modulation format is investigated. The factors that affect the transmission performance, such as the FSK tone space, dispersion compensation and coupler split ratio, are studied by numerical simulation. The proposed scheme is also experimentally demonstrated with a transmission of 155 Mbit/s FSK label combined with 10 Gbit/s ASK payload.
基金supported by the National Natural Science Foundation of China(61372069)and the"111"Project(B08038)
文摘In order to apply compressive sensing in wireless sensor network, inside the nodes cluster classified by the spatial correlation, we propose that a cluster head adopts free space optical communication with space division multiple access, and a sensor node uses a modulating retro-reflector for communication. Thus while a random sampling matrix is used to guide the establishment of links between head cluster and sensor nodes, the random linear projection is accomplished. To establish multiple links at the same time, an optical space division multiple access antenna is designed. It works in fixed beams switching mode and consists of optic lens with a large field of view(FOV), fiber array on the focal plane which is used to realize virtual channels segmentation, direction of arrival sensor, optical matrix switch and controller. Based on the angles of nodes' laser beams, by dynamically changing the route, optical matrix switch actualizes the multi-beam full duplex tracking receiving and transmission. Due to the structure of fiber array, there will be several fade zones both in the focal plane and in lens' FOV. In order to lower the impact of fade zones and harmonize multibeam, a fiber array adjustment is designed. By theoretical, simulated and experimental study, the antenna's qualitative feasibility is validated.
基金Project supported by the National Natural Science Foundation of China (Grant No 10674051)the Natural Science Foundation of Guangdong province, China (Grant No 06025082)+1 种基金the Program for Innovative Research Team of the Higher Education in Guangdong (Grant No 06CXTD005)the Program for New Century Excellent Talents (NCET) in University of China (Grant No ncet-04-0829)
文摘Application of the pressure controlled isothermal heating vertical deposition method to the fabrication of colloidal photonic crystals is systematically investigated in this paper. The fabricated samples are characterized by scanning electron microscope and transmission spectrum. High-quality samples with large transmissions in the pass bands and the sharp band edges are obtained and the optimum growth condition is determined. For the best sample, the transmission in the pass bands approaches 0.9 while that in the band gap reaches 0.1. More importantly, the maximum differential transmission as high as 0.1/nm is achieved. In addition, it is found that the number of stacking layers does not increase linearly with concentration of PS spheres in a solution, and a gradual saturation occurs when the concentration of PS spheres exceeds 1.5 wt.%. The uniformity of the fabricated samples is examined by transmission measurements on areas with different sizes. Finally, the tolerance of the fabricated samples to baking was studied.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61372076 and 61301171)the 111 Project(Grant No.B08038)+1 种基金the Fundamental Research Funds for the Central Universities(Grant No.K5051201021)the Scholarship from China Scholarship Council(Grant No.201308615037)
文摘Optical switch fabric plays an important role in building multiple-user optical quantum communication networks.Owing to its self-routing property and low complexity, a banyan network is widely used for building switch fabric. While,there is no efficient way to remove internal blocking in a banyan network in a classical way, quantum state fusion, by which the two-dimensional internal quantum states of two photons could be combined into a four-dimensional internal state of a single photon, makes it possible to solve this problem. In this paper, we convert the output mode of quantum state fusion from spatial-polarization mode into time-polarization mode. By combining modified quantum state fusion and quantum state fission with quantum Fredkin gate, we propose a practical scheme to build an optical quantum switch unit which is block free. The scheme can be extended to building more complex units, four of which are shown in this paper.
基金National Key Research and Development Program of China(2019YFB2203602)National Science Fund for Distinguished Young Scholars(61825504).
文摘We report a strict non-blocking four-port optical router that is used for a mesh photonic network-on-chip on a silicon-on-insulator platform.The router consists of eight silicon microring switches that are tuned by the thermo-optic effect.For each tested rousting state,the signal-to-noise ratio of the optical router is larger than 13.8 dB at the working wavelength.The routing functionality of the device is verified.We perform 40 Gbps nonreturn to zero code data transmission on its 12 optical links.Meanwhile,data transmission using wavelength division multiplexing on eight channels in the C band(from 1525 to 1565 nm)has been adopted to increase the communication capacity.The optical router’s average energy efficiency is 25.52 fJ/bit.The rising times(10%to 90%)of the eight optical switch elements are less than 10μs and the falling times(90%-10%)are less than 20μs.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 10974060 and 10774050 )the Program for Innovative Research Team of the Higher Education of Guangdong Province of China (Grant No. 06CXTD005)
文摘This paper demonstrates the realization of an optical switch by optically manipulating a large number of polystyrene spheres contained in a capillary. The strong scattering force exerted on polystyrene spheres with a large diameter of 4.3 μm is employed to realize the switching operation. A transparent window is opened for the signal light when the polystyrene spheres originally located at the beam centre are driven out of the beam region by the strong scattering force induced by the control light. The switching dynamics under different incident powers is investigated and compared with that observed in the optical switch based on the formation of optical matter. It is found that a large extinction ratio of - 30 dB and fast switching-on and switching-off times can be achieved in this type of switch.
基金Project supported by the National Natural Sciences Foundation of China(Grant Nos.61605225,11547035,11505100,11575071,11604147,and91321101)the Natural Science Foundation of Shanghai(Grant No.16ZR1448400)+2 种基金the Natural Science Foundation of Shandong Province,China(Grant No.ZR2015AQ007)the Strategic Priority Research Program(Grant No.XDB01010200)the Hundred Talents Program of the Chinese Academy of Sciences(Grant No.Y321311401)
文摘To promote the future quantum information technologies, we demonstrate an electrically driven optical switch based on quantum interference in a hybrid opto-electromechanical system, which consists of an opto-mechanical cavity and an external electric circuit. The key element of our scheme is a moveable mirror of cavity as a charged mechanical oscillator capacitively coupled to a fixed charged plate in a variable capacitor. By adjusting the voltage of the capacitor, the displacement of the moveable mirror is modulated, then the cavity field can be electrically turned on or off due to the detuning of the cavity. Based on the cavity induced transparency, the transparency window can be electrically switched on or off by turning on or off the cavity field. Therefore, the susceptibility of the medium in the cavity can be electrically controlled, i.e., the scheme of the electrically controlled absorption switching can be demonstrated. This electrically driven optical switch will excite a development trend and implementation prospect towards the integration and miniaturization of quantum module device in a chip.
文摘The effect of queuing delay of output buffer on the crosstalk property in optical packet switching nodes is investigated. The relationship between crosstalk and buffer length is obtained. From the calculation and simulation results, it is concluded that the crosstalk power penalty predominantly depends on the buffer length, the longer the buffer, the greater the penalty, as well as the random range of the penalty. While comparing with the effect of queuing delay, the effect of random routing path delay takes very little proportion in the total power penalty.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 10934010 and 60978019)
文摘We investigate the nonlinear dynamics of a system composed of a cigar-shaped Bose-Einstein condensate and an optical cavity with the two sides coupled dispersively.By adopting discrete-mode approximation for the condensate,taking atom loss as a necessary part of the model to analyze the evolution of the system,while using trial and error method to find out steady states of the system as a reference,numerical simulation demonstrates that with a constant pump,atom loss will trigger a quantum optical bi-stability switch,which predicts a new interesting phenomenon for experiments to verify.
基金supported by National Natural Science Foundation of China (Grant No 60677004)National High Technology 863 Research and Development Program of China (Grant Nos 2007AA01Z260,2007AA03Z447 and 2009AA01Z220)+4 种基金Key Project of the Chinese Ministry of Education (Grant No 107011)Key Laboratory of Broadband Optical Fiber Transmission and Communication Networks (UESTC) (Ministry of Education)Teaching and Scientific Research Foundation for the Returned Overseas Chinese Scholars (State Education Ministry)the Corporative Building Project of Beijing Educational Committee (Grant NoXK100130737)Program for New Century Excellent Talents in University of China (Grant No NECT-07-0111)
文摘This paper introduces the mid-span spectral inversion by four-wave mixing in a commercially available semiconductor optical amplifier (SOA) with a length of about 1.5 mm to optical label switching network based on combined frequency shift keying (FSK)-intensiy modulation (IM)/optical label-packet modulation to overcome the dispersion limitation of fiber. The 155 Mb/s-10 Gb/s combined FSK/IM signal is experimentally transmitted over a 100 km standard single mode fiber. 10^-10 and 10^-9 BER (bit error ratio), or even better, is achieved for the FSK label and IM packet, respectively. The -19 dB power conversion efficiency is obtained for -1 nm wavelength detuning.