We propose a simple all-optical diode which is comprised of an asymmetric ring cavity containing a two-level atomic ensemble. Attributed to spatial symmetry breaking of the ring cavity, direction-dependent optical bis...We propose a simple all-optical diode which is comprised of an asymmetric ring cavity containing a two-level atomic ensemble. Attributed to spatial symmetry breaking of the ring cavity, direction-dependent optical bistability is obtained in a classical bistable system. Therefore, a giant optical non-reciprocity is generated, which guarantees an all-optical diode with a high contrast up to 22 d B. Furthermore, its application as an all-optical logic AND gate is also discussed.展开更多
Using Terahertz Optical Asymmetric Demultiplexer (TOAD) based switch we have designed all-optical parallel half adder and full adder. The approach to design this all-optical arithmetic circuit not only enhances the co...Using Terahertz Optical Asymmetric Demultiplexer (TOAD) based switch we have designed all-optical parallel half adder and full adder. The approach to design this all-optical arithmetic circuit not only enhances the computational speed but also is capable of synthesizing light as input to produce desire output. The main advantage of parallel circuit is synchronization of input which is not required. All the circuits are designed theoretically and verified through numerical simulations.展开更多
An all-optical 3:8 decoder unit with the help of terahertz optical asymmetric demultiplexer (TOAD) is proposed. The all-optical 3:8 decoder unit with a set of all-optical full-adders and optical exclusive-ORs (XORs), ...An all-optical 3:8 decoder unit with the help of terahertz optical asymmetric demultiplexer (TOAD) is proposed. The all-optical 3:8 decoder unit with a set of all-optical full-adders and optical exclusive-ORs (XORs), can be used to perform a fast central processor unit using optical hardware components. We try to exploit the advantages of TOAD-based optical switch to design an integrated all-optical circuit which can perform decoding of signal. A theoretical model is presented and verified through numerical simulation. The new method promises both higher processing speed and accuracy. The model can be extended for studying more complex all-optical circuit of enhanced functionality in which decoder is the basic building block. The operation of the proposed circuit is parallel in nature. The impact of the switching energy with small signal gain and variation of extinction ratio and contrast ration with control pulse energy of the switching outcome is explored and assessed by means of numerical simulations.展开更多
Taking the advantage of ultrafast optical linear and nonlinear effects, all-optical signal processing(AOSP) enables manipulation, regeneration, and computing of information directly in optical domain without resorting...Taking the advantage of ultrafast optical linear and nonlinear effects, all-optical signal processing(AOSP) enables manipulation, regeneration, and computing of information directly in optical domain without resorting to electronics. As a promising photonic integration platform, silicon-on-insulator(SOI) has the advantage of complementary metal oxide semiconductor(CMOS) compatibility, low-loss, compact size as well as large optical nonlinearities. In this paper, we review the recent progress in the project granted to develop silicon-based reconfigurable AOSP chips, which aims to combine the merits of AOSP and silicon photonics to solve the unsustainable cost and energy challenges in future communication and big data applications. Three key challenges are identified in this project:(1) how to finely manipulate and reconfigure optical fields,(2) how to achieve ultra-low loss integrated silicon waveguides and significant enhancement of nonlinear effects,(3) how to mitigate crosstalk between optical, electrical and thermal components. By focusing on these key issues, the following major achievements are realized during the project. First, ultra-low loss silicon-based waveguides as well as ultra-high quality microresonators are developed by advancing key fabrication technologies as well as device structures. Integrated photonic filters with bandwidth and free spectral range reconfigurable in a wide range were realized to finely manipulate and select input light fields with a high degree of freedom. Second, several mechanisms and new designs that aim at nonlinear enhancement have been proposed, including optical ridge waveguides with reverse biased PIN junction, slot waveguides,multimode waveguides and parity-time symmetry coupled microresonators. Advanced AOSP operations are verified with these novel designs. Logical computations at 100 Gbit/s were demonstrated with self-developed, monolithic integrated programmable optical logic array. High-dimensional multi-value logic operations based on the four-wave mixing effect are realized. Multi-channel all-optical amplitude and phase regeneration technology is developed, and a multi-channel, multiformat, reconfigurable all-optical regeneration chip is realized. Expanding regeneration capacity via spatial dimension is also verified. Third, the crosstalk from optical as well as thermal coupling due to high-density integration are mitigated by developing novel optical designs and advanced packaging technologies, enabling high-density, small size, multi-channel and multi-functional operation with low power consumption. Finally, four programmable AOSP chips are developed, i.e.,programmable photonic filter chip, programmable photonic logic operation chip, multi-dimensional all-optical regeneration chip, and multi-channel and multi-functional AOSP chip with packaging. The major achievements developed in this project pave the way toward ultra-low loss, high-speed, high-efficient, high-density information processing in future classical and non-classical communication and computing applications.展开更多
Plasmon induced transparency(PIT)in the transparent window provides new insights into the design of optical filters,switches and storage,and integrated optics.The slow light effect makes PIT applicable to both sensors...Plasmon induced transparency(PIT)in the transparent window provides new insights into the design of optical filters,switches and storage,and integrated optics.The slow light effect makes PIT applicable to both sensors and slow light devices.Besides,PIT can overcome the diffraction limit of light,which makes it possible to manipulate light on a half-wavelength scale and brings good news to the miniaturization of optical devices.In this paper,we first summarize the researches of PIT phenomenon based on metal-dielectric-metal(MDM)waveguide systems and analyze the physical mechanisms of PIT including bright-dark mode interactions and phase-coupling-induced transparency.Then,we review the applications of PIT in optical sensing,optical filtering,optical switching,slow light devices and optical logic devices.At last,we outline important challenges that need to be addressed,provide corresponding solutions and predict important directions for future research in this area.展开更多
The parallel synchronization of three chaotic lasers is used to emulate optoelectronic logic NOR and XNOR gates via modulating the light and the current. We deduce a logical computational equation that governs the cha...The parallel synchronization of three chaotic lasers is used to emulate optoelectronic logic NOR and XNOR gates via modulating the light and the current. We deduce a logical computational equation that governs the chaotic synchronization, logical input, and logical output. We construct fundamental gates based on the three chaotic lasers and define the computational principle depending on the parallel synchronization. The logic gate can be implemented by appropriately synchronizing two chaotic lasers. The system shows practicability and flexibility because it can emulate synchronously an XNOR gate, two NOR gates, and so on. The synchronization can still be deteceted when mismatches exist with a certain range.展开更多
Due to the demand of high computational speed for processing big data that requires complex data manipulations in a timely manner,the need for extending classical logic to construct new multi-valued optical models bec...Due to the demand of high computational speed for processing big data that requires complex data manipulations in a timely manner,the need for extending classical logic to construct new multi-valued optical models becomes a challenging and promising research area.This paper establishes a novel octal-valued logic design model with new optical gates construction based on the hypothesis of Light Color State Model to provide an efficient solution to the limitations of computational processing inherent in the electronics computing.We provide new mathematical definitions for both of the binary OR function and the PLUS operation in multi valued logic that is used as the basis of novel construction for the optical full adder model.Four case studies were used to assure the validity of the proposed adder.These cases proved that the proposed optical 8-valued logic models provide significantly more information to be packed within a single bit and therefore the abilities of data representation and processing is increased.展开更多
This paper gives a brief introduction to our recent works on photonic crystal(Ph C) cavities and related integrated optical structures and devices. Theoretical background and numerical methods for simulation of Ph C c...This paper gives a brief introduction to our recent works on photonic crystal(Ph C) cavities and related integrated optical structures and devices. Theoretical background and numerical methods for simulation of Ph C cavities are first presented. Based on the theoretical basis, two relevant quantities, the cavity mode volume and the quality factor are discussed. Then the methods of fabrication and characterization of silicon Ph C slab cavities are introduced. Several types of Ph C cavities are presented, such as the usual L3 missing-hole cavity, the new concept waveguide-like parallel-hetero cavity, and the low-index nanobeam cavity. The advantages and disadvantages of each type of cavity are discussed. This will help the readers to decide which type of Ph C cavities to use in particular applications. Furthermore, several integrated optical devices based on Ph C cavities, such as optical filters, channel-drop filters, optical switches, and optical logic gates are described in both the working principle and operation characteristics. These devices designed and realized in our group demonstrate the wide range of applications of Ph C cavities and offer possible solutions to some integrated optical problems.展开更多
Photonic crystal based ring resonators are best choice for designing all-optical devices. In this paper, we used a basic structure of photonic crystal ring resonators and designed all optical logic gates which are wor...Photonic crystal based ring resonators are best choice for designing all-optical devices. In this paper, we used a basic structure of photonic crystal ring resonators and designed all optical logic gates which are working using the Kerr effect. The proposed gates consisted of upper and lower wavegnides coupled through a resonator which was designed for dropping of special wavelength. The resonance wavelength was designed for 1550 nm telecom operation wavelength. We used numerical meth- ods such as plane wave expansion and finite difference time domain （FDTD） for performing our simulations and studied the optical properties of the proposed structures. Our results showed that the critical input power for triggering the gate output was lower compared to previously reported gates.展开更多
Network coding brings many benefits for multicast networks. It is necessary to introduce network coding into optical networks. Nevertheless, the traditional network coding scheme is hard to be implemented in optical n...Network coding brings many benefits for multicast networks. It is necessary to introduce network coding into optical networks. Nevertheless, the traditional network coding scheme is hard to be implemented in optical networks because of the weak operation capability in photonic domain. In the paper, we focused on realizing two-channel network coding in all-optical multicast networks. An optical network coding scheme which can be realized via logic shift and logic XOR operations in photonic domain was proposed. Moreover, to perform the network coding scheme the coding node structure was designed and the operation principle and processes were illustrated in detail. In the end of the paper, the performance and the cost of different all-optical multicast mode were compared and analyzed.展开更多
Graphdiyne(GDY)is emerging as a promising material for various applications owing to its unique structure and fascinating properties.However,the application of GDY in electronics and optoelectronics are still in its i...Graphdiyne(GDY)is emerging as a promising material for various applications owing to its unique structure and fascinating properties.However,the application of GDY in electronics and optoelectronics are still in its infancy,primarily owing to the huge challenge in the synthesis of large-area and uniform GDY film for scalable applications.Here a modified van der Waals epitaxy strategy is proposed to synthesize wafer-scale GDY film with high uniformity and controllable thickness directly on graphene(Gr)surface,providing an ideal platform to construct large-scale GDY/Gr-based optoelectronic synapse array.Essential synaptic behaviors have been realized,and the linear and symmetric conductance-update characteristics facilitate the implementation of neuromorphic computing for image recognition with high accuracy and strong fault tolerance.Logic functions including“NAND”and“NOR”are integrated into the synapse which can be executed in an optical pathway.Moreover,a visible information sensing-memory-processing system is constructed to execute real-time image acquisition,in situ image memorization and distinction tasks,avoiding the time latency and energy consumption caused by data conversion and transmission in conventional visual systems.These results highlight the potential of GDY in applications of neuromorphic computing and artificial visual systems.展开更多
The unipolar photocurrent in conventional photodiodes(PDs)based on photovoltaic effect limits the output modes and potential versatility of these devices in photodetection.Bipolar photodiodes with photocurrent switchi...The unipolar photocurrent in conventional photodiodes(PDs)based on photovoltaic effect limits the output modes and potential versatility of these devices in photodetection.Bipolar photodiodes with photocurrent switching are emerging as a promising solution for obtaining photoelectric devices with unique and attractive functions,such as optical logic operation.Here,we design an all-solid-state chip-scale ultraviolet(UV)PD based on a hybrid GaN heterojunction with engineered bipolar polarized electric field.By introducing the polarization-induced photocurrent switching effect,the photocurrent direction can be switched in response to the wavelength of incident light at 0 V bias.In particular,the photocurrent direction exhibits negative when the irradiation wavelength is less than 315 nm,but positive when the wavelength is longer than 315 nm.The device shows a responsivity of up to−6.7 mA/W at 300 nm and 5.3 mA/W at 340 nm,respectively.In particular,three special logic gates in response to different dual UV light inputs are demonstrated via a single bipolar PD,which may be beneficial for future multifunctional UV photonic integrated devices and systems.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.11274242,11474221,and 11574229)the Joint Fund of the National Natural Science Foundation of China and the China Academy of Engineering Physics(Grant No.U1330203)the National Key Basic Research Special Foundation of China(Grant Nos.2011CB922203 and 2013CB632701)
文摘We propose a simple all-optical diode which is comprised of an asymmetric ring cavity containing a two-level atomic ensemble. Attributed to spatial symmetry breaking of the ring cavity, direction-dependent optical bistability is obtained in a classical bistable system. Therefore, a giant optical non-reciprocity is generated, which guarantees an all-optical diode with a high contrast up to 22 d B. Furthermore, its application as an all-optical logic AND gate is also discussed.
文摘Using Terahertz Optical Asymmetric Demultiplexer (TOAD) based switch we have designed all-optical parallel half adder and full adder. The approach to design this all-optical arithmetic circuit not only enhances the computational speed but also is capable of synthesizing light as input to produce desire output. The main advantage of parallel circuit is synchronization of input which is not required. All the circuits are designed theoretically and verified through numerical simulations.
文摘An all-optical 3:8 decoder unit with the help of terahertz optical asymmetric demultiplexer (TOAD) is proposed. The all-optical 3:8 decoder unit with a set of all-optical full-adders and optical exclusive-ORs (XORs), can be used to perform a fast central processor unit using optical hardware components. We try to exploit the advantages of TOAD-based optical switch to design an integrated all-optical circuit which can perform decoding of signal. A theoretical model is presented and verified through numerical simulation. The new method promises both higher processing speed and accuracy. The model can be extended for studying more complex all-optical circuit of enhanced functionality in which decoder is the basic building block. The operation of the proposed circuit is parallel in nature. The impact of the switching energy with small signal gain and variation of extinction ratio and contrast ration with control pulse energy of the switching outcome is explored and assessed by means of numerical simulations.
基金supported by the National Key Research and Development Program of China(No.2019YFB2203100).
文摘Taking the advantage of ultrafast optical linear and nonlinear effects, all-optical signal processing(AOSP) enables manipulation, regeneration, and computing of information directly in optical domain without resorting to electronics. As a promising photonic integration platform, silicon-on-insulator(SOI) has the advantage of complementary metal oxide semiconductor(CMOS) compatibility, low-loss, compact size as well as large optical nonlinearities. In this paper, we review the recent progress in the project granted to develop silicon-based reconfigurable AOSP chips, which aims to combine the merits of AOSP and silicon photonics to solve the unsustainable cost and energy challenges in future communication and big data applications. Three key challenges are identified in this project:(1) how to finely manipulate and reconfigure optical fields,(2) how to achieve ultra-low loss integrated silicon waveguides and significant enhancement of nonlinear effects,(3) how to mitigate crosstalk between optical, electrical and thermal components. By focusing on these key issues, the following major achievements are realized during the project. First, ultra-low loss silicon-based waveguides as well as ultra-high quality microresonators are developed by advancing key fabrication technologies as well as device structures. Integrated photonic filters with bandwidth and free spectral range reconfigurable in a wide range were realized to finely manipulate and select input light fields with a high degree of freedom. Second, several mechanisms and new designs that aim at nonlinear enhancement have been proposed, including optical ridge waveguides with reverse biased PIN junction, slot waveguides,multimode waveguides and parity-time symmetry coupled microresonators. Advanced AOSP operations are verified with these novel designs. Logical computations at 100 Gbit/s were demonstrated with self-developed, monolithic integrated programmable optical logic array. High-dimensional multi-value logic operations based on the four-wave mixing effect are realized. Multi-channel all-optical amplitude and phase regeneration technology is developed, and a multi-channel, multiformat, reconfigurable all-optical regeneration chip is realized. Expanding regeneration capacity via spatial dimension is also verified. Third, the crosstalk from optical as well as thermal coupling due to high-density integration are mitigated by developing novel optical designs and advanced packaging technologies, enabling high-density, small size, multi-channel and multi-functional operation with low power consumption. Finally, four programmable AOSP chips are developed, i.e.,programmable photonic filter chip, programmable photonic logic operation chip, multi-dimensional all-optical regeneration chip, and multi-channel and multi-functional AOSP chip with packaging. The major achievements developed in this project pave the way toward ultra-low loss, high-speed, high-efficient, high-density information processing in future classical and non-classical communication and computing applications.
基金Project(2018JJ4086)supported by the Natural Science Foundation of Hunan Province,ChinaProject(520)supported by the Training and Innovation Base for Graduate of Education Department of Hunan Province,China+1 种基金Project(201802368048)supported by Industry-University Cooperation and Education Project of National Education Department,ChinaProject(CSUZC201925)supported by the Open Sharing Fund for the Large-scale Instruments and Equipments of Central South University,China。
文摘Plasmon induced transparency(PIT)in the transparent window provides new insights into the design of optical filters,switches and storage,and integrated optics.The slow light effect makes PIT applicable to both sensors and slow light devices.Besides,PIT can overcome the diffraction limit of light,which makes it possible to manipulate light on a half-wavelength scale and brings good news to the miniaturization of optical devices.In this paper,we first summarize the researches of PIT phenomenon based on metal-dielectric-metal(MDM)waveguide systems and analyze the physical mechanisms of PIT including bright-dark mode interactions and phase-coupling-induced transparency.Then,we review the applications of PIT in optical sensing,optical filtering,optical switching,slow light devices and optical logic devices.At last,we outline important challenges that need to be addressed,provide corresponding solutions and predict important directions for future research in this area.
基金supported by the National Natural Science Foundation of China(Grant No.11204139)
文摘The parallel synchronization of three chaotic lasers is used to emulate optoelectronic logic NOR and XNOR gates via modulating the light and the current. We deduce a logical computational equation that governs the chaotic synchronization, logical input, and logical output. We construct fundamental gates based on the three chaotic lasers and define the computational principle depending on the parallel synchronization. The logic gate can be implemented by appropriately synchronizing two chaotic lasers. The system shows practicability and flexibility because it can emulate synchronously an XNOR gate, two NOR gates, and so on. The synchronization can still be deteceted when mismatches exist with a certain range.
文摘Due to the demand of high computational speed for processing big data that requires complex data manipulations in a timely manner,the need for extending classical logic to construct new multi-valued optical models becomes a challenging and promising research area.This paper establishes a novel octal-valued logic design model with new optical gates construction based on the hypothesis of Light Color State Model to provide an efficient solution to the limitations of computational processing inherent in the electronics computing.We provide new mathematical definitions for both of the binary OR function and the PLUS operation in multi valued logic that is used as the basis of novel construction for the optical full adder model.Four case studies were used to assure the validity of the proposed adder.These cases proved that the proposed optical 8-valued logic models provide significantly more information to be packed within a single bit and therefore the abilities of data representation and processing is increased.
基金supported by the National Natural Fundamental Research Program of China(Grant Nos.2006CB921702,2007CB613205,2011CB922002 and 2012CB922103)the National Natural Science Foundation of China(Grant Nos.10525419,11375067,11275074,11374116 and 11204096)
文摘This paper gives a brief introduction to our recent works on photonic crystal(Ph C) cavities and related integrated optical structures and devices. Theoretical background and numerical methods for simulation of Ph C cavities are first presented. Based on the theoretical basis, two relevant quantities, the cavity mode volume and the quality factor are discussed. Then the methods of fabrication and characterization of silicon Ph C slab cavities are introduced. Several types of Ph C cavities are presented, such as the usual L3 missing-hole cavity, the new concept waveguide-like parallel-hetero cavity, and the low-index nanobeam cavity. The advantages and disadvantages of each type of cavity are discussed. This will help the readers to decide which type of Ph C cavities to use in particular applications. Furthermore, several integrated optical devices based on Ph C cavities, such as optical filters, channel-drop filters, optical switches, and optical logic gates are described in both the working principle and operation characteristics. These devices designed and realized in our group demonstrate the wide range of applications of Ph C cavities and offer possible solutions to some integrated optical problems.
文摘Photonic crystal based ring resonators are best choice for designing all-optical devices. In this paper, we used a basic structure of photonic crystal ring resonators and designed all optical logic gates which are working using the Kerr effect. The proposed gates consisted of upper and lower wavegnides coupled through a resonator which was designed for dropping of special wavelength. The resonance wavelength was designed for 1550 nm telecom operation wavelength. We used numerical meth- ods such as plane wave expansion and finite difference time domain （FDTD） for performing our simulations and studied the optical properties of the proposed structures. Our results showed that the critical input power for triggering the gate output was lower compared to previously reported gates.
基金supported by the National Natural Science Foundation of China (61171103)the Doctoral Research Fund of Shandong University of Technology (4041-411023)
文摘Network coding brings many benefits for multicast networks. It is necessary to introduce network coding into optical networks. Nevertheless, the traditional network coding scheme is hard to be implemented in optical networks because of the weak operation capability in photonic domain. In the paper, we focused on realizing two-channel network coding in all-optical multicast networks. An optical network coding scheme which can be realized via logic shift and logic XOR operations in photonic domain was proposed. Moreover, to perform the network coding scheme the coding node structure was designed and the operation principle and processes were illustrated in detail. In the end of the paper, the performance and the cost of different all-optical multicast mode were compared and analyzed.
基金This work was supported by the National Natural Science Foundation of China(Nos.21790052 and 51802220)Natural Science Foundation of Tianjin City(No.19JCYBJC17300).
文摘Graphdiyne(GDY)is emerging as a promising material for various applications owing to its unique structure and fascinating properties.However,the application of GDY in electronics and optoelectronics are still in its infancy,primarily owing to the huge challenge in the synthesis of large-area and uniform GDY film for scalable applications.Here a modified van der Waals epitaxy strategy is proposed to synthesize wafer-scale GDY film with high uniformity and controllable thickness directly on graphene(Gr)surface,providing an ideal platform to construct large-scale GDY/Gr-based optoelectronic synapse array.Essential synaptic behaviors have been realized,and the linear and symmetric conductance-update characteristics facilitate the implementation of neuromorphic computing for image recognition with high accuracy and strong fault tolerance.Logic functions including“NAND”and“NOR”are integrated into the synapse which can be executed in an optical pathway.Moreover,a visible information sensing-memory-processing system is constructed to execute real-time image acquisition,in situ image memorization and distinction tasks,avoiding the time latency and energy consumption caused by data conversion and transmission in conventional visual systems.These results highlight the potential of GDY in applications of neuromorphic computing and artificial visual systems.
基金supported by the National Natural Science Foundation of China(Nos.62027818,51861135105,61874034,and 11974320)the National Key Research and Development Program of China(No.2021YFB3202500)International Science and Technology Cooperation Program of Shanghai Science and Technology Innovation Action Plan(No.21520713300).
文摘The unipolar photocurrent in conventional photodiodes(PDs)based on photovoltaic effect limits the output modes and potential versatility of these devices in photodetection.Bipolar photodiodes with photocurrent switching are emerging as a promising solution for obtaining photoelectric devices with unique and attractive functions,such as optical logic operation.Here,we design an all-solid-state chip-scale ultraviolet(UV)PD based on a hybrid GaN heterojunction with engineered bipolar polarized electric field.By introducing the polarization-induced photocurrent switching effect,the photocurrent direction can be switched in response to the wavelength of incident light at 0 V bias.In particular,the photocurrent direction exhibits negative when the irradiation wavelength is less than 315 nm,but positive when the wavelength is longer than 315 nm.The device shows a responsivity of up to−6.7 mA/W at 300 nm and 5.3 mA/W at 340 nm,respectively.In particular,three special logic gates in response to different dual UV light inputs are demonstrated via a single bipolar PD,which may be beneficial for future multifunctional UV photonic integrated devices and systems.
