Recent experiments demonstrated that chiral symmetry breaking at an exceptional point(EP) is a viable route to achieve unidirectional laser emission in microring lasers. By a detailed semiconductor laser rate equation...Recent experiments demonstrated that chiral symmetry breaking at an exceptional point(EP) is a viable route to achieve unidirectional laser emission in microring lasers. By a detailed semiconductor laser rate equation model,we show here that unidirectional laser emission at an EP is a robust regime. Slight deviations from the EP condition can break preferential unidirectional lasing near threshold via a Hopf instability. However, abovea "second" laser threshold, unidirectional emission is restored.展开更多
Non-Hermitian systems with their spectral degeneracies known as exceptional points(EPs)have been explored for lasing,controlling light transport,and enhancing a sensor’s response.A ring resonator can be brought to an...Non-Hermitian systems with their spectral degeneracies known as exceptional points(EPs)have been explored for lasing,controlling light transport,and enhancing a sensor’s response.A ring resonator can be brought to an EP by controlling the coupling between its frequency degenerate clockwise and counterclockwise traveling modes.This has been typically achieved by introducing two or more nanotips into the resonator’s mode volume.While this method provides a route to study EP physics,the basic understanding of how the nanotips’shape and size symmetry impact the system’s non-Hermicity is missing,along with additional loss from both in-plane and out-of-plane scattering.The limited resonance stability poses a challenge for leveraging EP effects for switches or modulators,which requires stable cavity resonance and fixed laser-cavity detuning.Here we use lithographically defined asymmetric and symmetric Mie scatterers,which enable subwavelength control of wave transmission and reflections without deflecting to additional radiation channels.We show that those pre-defined Mie scatterers can bring the system to an EP without post tuning,as well as enable chiral light transport within the resonator.Counterintuitively,the Mie scatterer results in enhanced quality factor measured on the transmission port,through coherently suppressing the backscattering from the waveguide surface roughness.The proposed device platform enables pre-defined chiral light propagation and backscattering-free resonances,needed for various applications such as frequency combs,solitons,sensing,and other nonlinear optical processes such as photon blockade,and regenerative oscillators.展开更多
We demonstrate a hybrid laser with a low intrinsic linewidth of 34.2 Hz and a high fiber-coupled output power of 11.7 dBm,by coupling a Si_(3)N_(4)-based subwavelength hole defect assisted microring reflector(SHDA-MRR...We demonstrate a hybrid laser with a low intrinsic linewidth of 34.2 Hz and a high fiber-coupled output power of 11.7 dBm,by coupling a Si_(3)N_(4)-based subwavelength hole defect assisted microring reflector(SHDA-MRR)to a commercially available distributed feedback semiconductor laser.The proposed SHDA-MRR structure features an accurately controlled reflection response,with the manipulated modal coupling between two degenerate counterpropagating modes induced by a subwavelength hole defect embedded in the microring waveguide.With further joint optimization of cavity parameters,this Si_(3)N_(4) SHDA-MRR structure is expected to reduce the laser intrinsic linewidth to a sub-hertz level.This work explores a low-cost and robust linewidth reduction scheme for the applications of high-speed coherent optical communications systems and high-resolution optical metrology.展开更多
The dynamic characteristics are investigated for a microring laser with an external radius of 12μm subject to external optical injection.Single-mode operation with a side mode suppression ratio of 33.4 dB is realized...The dynamic characteristics are investigated for a microring laser with an external radius of 12μm subject to external optical injection.Single-mode operation with a side mode suppression ratio of 33.4 dB is realized at a biasing current of 25 mA and a temperature of 290 K,and the corresponding small-signal modulation response is obtained with a resonance peak frequency of 7.5 GHz.Under the optical injection from a tunable laser,the improvements of the small-signal modulation response induced by four-wave mixing are observed for the microring laser,which shows an additional resonance peak around the frequency of the beat frequency between the lasing mode and the injecting light.Furthermore,optical generation of a microwave signal is realized by the light beating between the lasing mode and the injecting light measured by a high-speed photodetector and a spectrum analyzer.展开更多
With the rapid development of artificial intelligence and machine learning, brain-inspired neuromorphic photonics has emerged as an extremely attractive computing paradigm, promising orders-of-magnitude higher computi...With the rapid development of artificial intelligence and machine learning, brain-inspired neuromorphic photonics has emerged as an extremely attractive computing paradigm, promising orders-of-magnitude higher computing speed and energy efficiency compared to its electronic counterparts. Tremendous efforts have been devoted to photonic hardware implementations of mimicking the nonlinear neuron-like spiking response and the linear synapse-like weighting functionality. Here, we systematically characterize the spiking dynamics of a passive silicon microring neuron. The research of self-pulsation and excitability reveals that the silicon microring can function as an all-optical class Ⅱ resonate-and-fire neuron. The typical refractory period has been successfully suppressed by configuring the pump power above the perturbation power, hence allowing the microring neuron to operate with a speed up to roughly sub-gigahertz. Additionally, temporal integration and controllable inhibition regimes are experimentally demonstrated for the first time, to the best of our knowledge. Our experimental verification is obtained with a commercial CMOS platform, hence offering great potential for large-scale neuromorphic photonics integration.展开更多
We propose a novel high-performance digital optical sensor based on the Mach-Zehnder interferential effect and the dual-microring resonators with the waveguide-coupled feedback. The simulation results show that the se...We propose a novel high-performance digital optical sensor based on the Mach-Zehnder interferential effect and the dual-microring resonators with the waveguide-coupled feedback. The simulation results show that the sensitivity of the sensor can be orders of magnitude higher than that of aconventional sensor, and high quality factor is not critical in it. Moreover, by optimizing the length of the feedback waveguide to be equal to the perimeter of the ring, the measurement range of the proposed sensor is twice as much as that of the conventional sensor in the weak coupling case.展开更多
As an important computing operation,photonic matrix-vector multiplication is widely used in photonic neutral networks and signal processing.However,conventional incoherent matrix-vector multiplication focuses on real-...As an important computing operation,photonic matrix-vector multiplication is widely used in photonic neutral networks and signal processing.However,conventional incoherent matrix-vector multiplication focuses on real-valued operations,which cannot work well in complex-valued neural networks and discrete Fourier transform.In this paper,we propose a systematic solution to extend the matrix computation of microring arrays from the real-valued field to the complex-valued field,and from small-scale(i.e.,4×4)to large-scale matrix computation(i.e.,16×16).Combining matrix decomposition and matrix partition,our photonic complex matrix-vector multiplier chip can support arbitrary large-scale and complex-valued matrix computation.We further demonstrate Walsh-Hardmard transform,discrete cosine transform,discrete Fourier transform,and image convolutional processing.Our scheme provides a path towards breaking the limits of complex-valued computing accelerator in conventional incoherent optical architecture.More importantly,our results reveal that an integrated photonic platform is of huge potential for large-scale,complex-valued,artificial intelligence computing and signal processing.展开更多
An ultrafast microring modulator(MRM) is fabricated and presented with V_(π)· L of 0.825 V · cm. A 240 Gb/s PAM-8 signal transmission over 2 km standard single-mode fiber(SSMF) is experimentally demonstrate...An ultrafast microring modulator(MRM) is fabricated and presented with V_(π)· L of 0.825 V · cm. A 240 Gb/s PAM-8 signal transmission over 2 km standard single-mode fiber(SSMF) is experimentally demonstrated. PN junction doping concentration is optimized, and the overall performance of the MRM is improved. Optical peaking is introduced to further extend the EO bandwidth from 52 to 110 GHz by detuning the input wavelength. A titanium nitride heater with 0.1 nm/m W tuning efficiency is implemented above the MRM to adjust the resonant wavelength. High bit rate modulations based on the high-performance and compact MRM are carried out. By adopting off-line signal processing in the transmitter and receiver side, 120 Gb/s NRZ, 220 Gb/s PAM-4, and240 Gb/s PAM-8 are measured with the back-to-back bit error ratio(BER) of 5.5 × 10^(-4), 1.5 × 10^(-2), and 1.4 × 10^(-2), respectively. A BER with different received optical power and 2 km SSMF transmission is also investigated. The BER for 220 Gb/s PAM-4 and 240 Gb/s PAM-8 after 2 km SSMF transmission is calculated to be 1.7 × 10^(-2), and 1.5 × 10^(-2), which meet with the threshold of soft-decision forward-error correction,respectively.展开更多
Microring-based optical switches are promising for wavelength-selective switching with the merits of compact size and low power consumption.However,the large insertion loss,the high fabrication,and the temperature sen...Microring-based optical switches are promising for wavelength-selective switching with the merits of compact size and low power consumption.However,the large insertion loss,the high fabrication,and the temperature sensitivity hinder the scalability of silicon microring optical switch fabrics.In this paper,we utilize a three-dimensional(3D)microring-based optical switch element(SE)on a multi-layer Si_(3)N_(4)-on-SOI platform to realize highperformance large-scale optical switch fabrics.The 3D microring-based SE consists of a Si∕Si_(3)N_(4) waveguide overpass crossing in the bottom and the top layers,and Si_(3)N_(4) dual-coupled microring resonators(MRRs)in the middle layer.The switch is calibration-free and has low insertion loss.With the 3D microring-based SEs,we implement an 8×8 crossbar optical switch fabric.As the resonance wavelengths of all SEs are well aligned,only one SE needs to be turned on in each routing path,which greatly reduces the complexity of the switch control.The optical transmission spectra show a box-like shape,with a passband width of~69 GHz and an average on-state loss of~0.37 dB.The chip has a record-low on-chip insertion loss of 0.52-2.66 dB.We also implement a non-duplicate polarization-diversity optical switch by using the bidirectional transmission characteristics of the crossbar architecture,which is highly favorable for practical applications.100 Gb/s dual-polarization quadrature-phase-shift-keying(DP-QPSK)signal is transmitted through the switch without significant degradation.To the best of our knowledge,this is the first time that 3D MRRs have been used to build highly scalable polarization-diversity optical switch fabrics.展开更多
The silicon-based arrayed waveguide grating(AWG)is widely used due to its compact footprint and its compatibility with the mature CMOS process.However,except for AWGs with ridged waveguides of a few micrometers of cro...The silicon-based arrayed waveguide grating(AWG)is widely used due to its compact footprint and its compatibility with the mature CMOS process.However,except for AWGs with ridged waveguides of a few micrometers of cross section,any small process error will cause a large phase deviation in other AWGs,resulting in an increasing cross talk.In this paper,an ultralow cross talk AWG via a tunable microring resonator(MRR)filter is demonstrated on the SOI platform.The measured insertion loss and minimum adjacent cross talk of the designed AWG are approximately 3.2 and-45.1 d B,respectively.Compared with conventional AWG,its cross talk is greatly reduced.展开更多
Lens-like vaterite CaCO3 microrings composed of CaCO3 nanoparticles were synthesized via a microemulsion-mediated route at room temperature with ethanol and n-hexanol as co-surfactant. This process did not demand any ...Lens-like vaterite CaCO3 microrings composed of CaCO3 nanoparticles were synthesized via a microemulsion-mediated route at room temperature with ethanol and n-hexanol as co-surfactant. This process did not demand any additional energy such as heating or continuous agitation. It was the first time to use ethanol as co-surfactant in the synthesis of micro or nanomaterials. And the ethanol was believed to play an important role in the aggregation fashion of CaCO3 nanoparticles. Moreover, shuttle-shaped nanorods, hexagonal nanoplates, and rice-like nanoparticles were also fabricated by modulating the growth parameters. Additionally, the introduce of ethanol into microemulsions as co-surfactant may be generalized as a novel green route to control the structure of other functional materials.展开更多
We report on an eight-channel reconfigurable optical add-drop multiplexer based on cascaded microring resonators with a high tuning power consumption and a compact footprint. Microheaters are fabricated on top of the ...We report on an eight-channel reconfigurable optical add-drop multiplexer based on cascaded microring resonators with a high tuning power consumption and a compact footprint. Microheaters are fabricated on top of the microring resonators and can be modulated using the thermo-optic effect to achieve the reconfigurable functionality of the device. We demonstrate the reconfigurable add-drop multiplexing functionality for channel spacings of 1 O0 GHz and 50 GHz, with the centre wavelengths of the channels aligned to International Telecommunication Union grid specifications. The crosstalk for channel spacings of 100 GHz and 50 GHz are less than -22.5 dB and -15.5 dB, respectively. The average tuning efficiency is about 4.5 mW/nm, and the response speed is about 13.0 kHz.展开更多
The effects of manufacturing errors on transmission characteristics are analyzed for a polymer vertical coupling microring resonator.Calculated results show that the errors cause a shift and shape change of the transm...The effects of manufacturing errors on transmission characteristics are analyzed for a polymer vertical coupling microring resonator.Calculated results show that the errors cause a shift and shape change of the transmission spectrum compared to the designed case without errors.Furthermore,accumulation and compensation for the errors is researched.In order to realize the normal filtering for the fabricated microring resonator device,some allowed errors are discussed.展开更多
This paper investigated the design and the characterization of a photonic delay line based on passive cascaded silicon-on-insulator （SOI） microrings. We considered the compromise of group delay, bandwidth and insert...This paper investigated the design and the characterization of a photonic delay line based on passive cascaded silicon-on-insulator （SOI） microrings. We considered the compromise of group delay, bandwidth and insertion loss. A 3-stage double channel side-coupled integrated spaced sequence of resonator （SCISSOR） device was optimized by shifting the resonance of each microring and fabricated with electron beam lithography and dry etching. The group delay was measured to be 17 ps for non-return-to-zero signals at different bit rates and the bandwidth of 78 GHz was achieved. The experiment result agreed well with our simulation.展开更多
A modulator is an essential building block in the integrated photonics,connecting the electrical with optical signals.The microring modulator gains much attention because of the small footprint,low drive voltage and h...A modulator is an essential building block in the integrated photonics,connecting the electrical with optical signals.The microring modulator gains much attention because of the small footprint,low drive voltage and high extinction ratio.An ultra-low V_(pp)and high-modulation-depth indium phosphide-based racetrack microring modulator is demonstrated in this paper.The proposed device mainly comprises one racetrack microring,incorporating a semiconductor amplifier,and coupling with a bus waveguide through a multimode interference coupler.Traveling wave electrodes are employed to supply bidirectional bias ports,terminating with a 50-Ω impedance.The on/off extinction ratio of the microring reaches 43.3 dB due to the delicately tuning of the gain.An 11 mV V_(pp),a maximum 42.5 dB modulation depth and a 6.6 GHz bandwidth are realized,respectively.This proposed microring modulator could enrich the functionalities and designability of the fundamental integrated devices.展开更多
基金National Science Foundation(NSF)(DMR-1506884)Army Research Office(ARO)(W911NF-15-1-0152)
文摘Recent experiments demonstrated that chiral symmetry breaking at an exceptional point(EP) is a viable route to achieve unidirectional laser emission in microring lasers. By a detailed semiconductor laser rate equation model,we show here that unidirectional laser emission at an EP is a robust regime. Slight deviations from the EP condition can break preferential unidirectional lasing near threshold via a Hopf instability. However, abovea "second" laser threshold, unidirectional emission is restored.
基金supported by Defense Advanced Research Projects Agency(N660012114034)Air Force Office of Scientific Research(AFOSR)Multi-University Research Initiative(FA9550-21-1-0202)+1 种基金AFOSR(FA9550-18-1-0235)partially supported by AFOSR(FA9550-18-1-0300).
文摘Non-Hermitian systems with their spectral degeneracies known as exceptional points(EPs)have been explored for lasing,controlling light transport,and enhancing a sensor’s response.A ring resonator can be brought to an EP by controlling the coupling between its frequency degenerate clockwise and counterclockwise traveling modes.This has been typically achieved by introducing two or more nanotips into the resonator’s mode volume.While this method provides a route to study EP physics,the basic understanding of how the nanotips’shape and size symmetry impact the system’s non-Hermicity is missing,along with additional loss from both in-plane and out-of-plane scattering.The limited resonance stability poses a challenge for leveraging EP effects for switches or modulators,which requires stable cavity resonance and fixed laser-cavity detuning.Here we use lithographically defined asymmetric and symmetric Mie scatterers,which enable subwavelength control of wave transmission and reflections without deflecting to additional radiation channels.We show that those pre-defined Mie scatterers can bring the system to an EP without post tuning,as well as enable chiral light transport within the resonator.Counterintuitively,the Mie scatterer results in enhanced quality factor measured on the transmission port,through coherently suppressing the backscattering from the waveguide surface roughness.The proposed device platform enables pre-defined chiral light propagation and backscattering-free resonances,needed for various applications such as frequency combs,solitons,sensing,and other nonlinear optical processes such as photon blockade,and regenerative oscillators.
基金National Key Research and Development Program of China(2018YFB2201802)National Natural Science Foundation of China(61771285).
文摘We demonstrate a hybrid laser with a low intrinsic linewidth of 34.2 Hz and a high fiber-coupled output power of 11.7 dBm,by coupling a Si_(3)N_(4)-based subwavelength hole defect assisted microring reflector(SHDA-MRR)to a commercially available distributed feedback semiconductor laser.The proposed SHDA-MRR structure features an accurately controlled reflection response,with the manipulated modal coupling between two degenerate counterpropagating modes induced by a subwavelength hole defect embedded in the microring waveguide.With further joint optimization of cavity parameters,this Si_(3)N_(4) SHDA-MRR structure is expected to reduce the laser intrinsic linewidth to a sub-hertz level.This work explores a low-cost and robust linewidth reduction scheme for the applications of high-speed coherent optical communications systems and high-resolution optical metrology.
基金the National Natural Science Foundation of China under Grants 61235004,61021003,and 61106048.
文摘The dynamic characteristics are investigated for a microring laser with an external radius of 12μm subject to external optical injection.Single-mode operation with a side mode suppression ratio of 33.4 dB is realized at a biasing current of 25 mA and a temperature of 290 K,and the corresponding small-signal modulation response is obtained with a resonance peak frequency of 7.5 GHz.Under the optical injection from a tunable laser,the improvements of the small-signal modulation response induced by four-wave mixing are observed for the microring laser,which shows an additional resonance peak around the frequency of the beat frequency between the lasing mode and the injecting light.Furthermore,optical generation of a microwave signal is realized by the light beating between the lasing mode and the injecting light measured by a high-speed photodetector and a spectrum analyzer.
基金National Key Research and Development Program of China(2019YFB2203101)National Natural Science Foundation of China(61805137,61835008,62175151)+1 种基金Natural Science Foundation of Shanghai(19ZR1475400)Open Project Program of Wuhan National Laboratory for Optoelectronics(2018WNLOKF012).
文摘With the rapid development of artificial intelligence and machine learning, brain-inspired neuromorphic photonics has emerged as an extremely attractive computing paradigm, promising orders-of-magnitude higher computing speed and energy efficiency compared to its electronic counterparts. Tremendous efforts have been devoted to photonic hardware implementations of mimicking the nonlinear neuron-like spiking response and the linear synapse-like weighting functionality. Here, we systematically characterize the spiking dynamics of a passive silicon microring neuron. The research of self-pulsation and excitability reveals that the silicon microring can function as an all-optical class Ⅱ resonate-and-fire neuron. The typical refractory period has been successfully suppressed by configuring the pump power above the perturbation power, hence allowing the microring neuron to operate with a speed up to roughly sub-gigahertz. Additionally, temporal integration and controllable inhibition regimes are experimentally demonstrated for the first time, to the best of our knowledge. Our experimental verification is obtained with a commercial CMOS platform, hence offering great potential for large-scale neuromorphic photonics integration.
基金Project supported by the National Basic Research Program of China(Grant No.2010CB327601)
文摘We propose a novel high-performance digital optical sensor based on the Mach-Zehnder interferential effect and the dual-microring resonators with the waveguide-coupled feedback. The simulation results show that the sensitivity of the sensor can be orders of magnitude higher than that of aconventional sensor, and high quality factor is not critical in it. Moreover, by optimizing the length of the feedback waveguide to be equal to the perimeter of the ring, the measurement range of the proposed sensor is twice as much as that of the conventional sensor in the weak coupling case.
基金This work was partially supported by the National Key Research and Development Project of China(No.2018YFB2201901)the National Natural Science Foundation of China(Grant Nos.61805090 and 62075075)+1 种基金Shenzhen Science and Technology Innovation Commission(No.SGDX2019081623060558)Research Grants Council of Hong Kong SAR(No.PolyU152241/18E).
文摘As an important computing operation,photonic matrix-vector multiplication is widely used in photonic neutral networks and signal processing.However,conventional incoherent matrix-vector multiplication focuses on real-valued operations,which cannot work well in complex-valued neural networks and discrete Fourier transform.In this paper,we propose a systematic solution to extend the matrix computation of microring arrays from the real-valued field to the complex-valued field,and from small-scale(i.e.,4×4)to large-scale matrix computation(i.e.,16×16).Combining matrix decomposition and matrix partition,our photonic complex matrix-vector multiplier chip can support arbitrary large-scale and complex-valued matrix computation.We further demonstrate Walsh-Hardmard transform,discrete cosine transform,discrete Fourier transform,and image convolutional processing.Our scheme provides a path towards breaking the limits of complex-valued computing accelerator in conventional incoherent optical architecture.More importantly,our results reveal that an integrated photonic platform is of huge potential for large-scale,complex-valued,artificial intelligence computing and signal processing.
基金National Key Research and Development Program of China(2019YFB2205200)National Natural Science Foundation of China(U21A20454).
文摘An ultrafast microring modulator(MRM) is fabricated and presented with V_(π)· L of 0.825 V · cm. A 240 Gb/s PAM-8 signal transmission over 2 km standard single-mode fiber(SSMF) is experimentally demonstrated. PN junction doping concentration is optimized, and the overall performance of the MRM is improved. Optical peaking is introduced to further extend the EO bandwidth from 52 to 110 GHz by detuning the input wavelength. A titanium nitride heater with 0.1 nm/m W tuning efficiency is implemented above the MRM to adjust the resonant wavelength. High bit rate modulations based on the high-performance and compact MRM are carried out. By adopting off-line signal processing in the transmitter and receiver side, 120 Gb/s NRZ, 220 Gb/s PAM-4, and240 Gb/s PAM-8 are measured with the back-to-back bit error ratio(BER) of 5.5 × 10^(-4), 1.5 × 10^(-2), and 1.4 × 10^(-2), respectively. A BER with different received optical power and 2 km SSMF transmission is also investigated. The BER for 220 Gb/s PAM-4 and 240 Gb/s PAM-8 after 2 km SSMF transmission is calculated to be 1.7 × 10^(-2), and 1.5 × 10^(-2), which meet with the threshold of soft-decision forward-error correction,respectively.
基金National Key Research and Development Program of China(2019YFB2203200)National Natural Science Foundation of China(62075128,62090052,62135010)Zhejiang Provincial Major Research and Development Program(2021C01199)。
文摘Microring-based optical switches are promising for wavelength-selective switching with the merits of compact size and low power consumption.However,the large insertion loss,the high fabrication,and the temperature sensitivity hinder the scalability of silicon microring optical switch fabrics.In this paper,we utilize a three-dimensional(3D)microring-based optical switch element(SE)on a multi-layer Si_(3)N_(4)-on-SOI platform to realize highperformance large-scale optical switch fabrics.The 3D microring-based SE consists of a Si∕Si_(3)N_(4) waveguide overpass crossing in the bottom and the top layers,and Si_(3)N_(4) dual-coupled microring resonators(MRRs)in the middle layer.The switch is calibration-free and has low insertion loss.With the 3D microring-based SEs,we implement an 8×8 crossbar optical switch fabric.As the resonance wavelengths of all SEs are well aligned,only one SE needs to be turned on in each routing path,which greatly reduces the complexity of the switch control.The optical transmission spectra show a box-like shape,with a passband width of~69 GHz and an average on-state loss of~0.37 dB.The chip has a record-low on-chip insertion loss of 0.52-2.66 dB.We also implement a non-duplicate polarization-diversity optical switch by using the bidirectional transmission characteristics of the crossbar architecture,which is highly favorable for practical applications.100 Gb/s dual-polarization quadrature-phase-shift-keying(DP-QPSK)signal is transmitted through the switch without significant degradation.To the best of our knowledge,this is the first time that 3D MRRs have been used to build highly scalable polarization-diversity optical switch fabrics.
基金supported by the National Key Research and Development Program of China(No.2018YFB2200500)the Yunnan Provincial Foundation Program(No.202201AT070202)the National Natural Science Foundation of China(No.62065010)。
文摘The silicon-based arrayed waveguide grating(AWG)is widely used due to its compact footprint and its compatibility with the mature CMOS process.However,except for AWGs with ridged waveguides of a few micrometers of cross section,any small process error will cause a large phase deviation in other AWGs,resulting in an increasing cross talk.In this paper,an ultralow cross talk AWG via a tunable microring resonator(MRR)filter is demonstrated on the SOI platform.The measured insertion loss and minimum adjacent cross talk of the designed AWG are approximately 3.2 and-45.1 d B,respectively.Compared with conventional AWG,its cross talk is greatly reduced.
基金Supported by the National Natural Science Foundation of China(No.20573017)the Natural Science Young Foundation of Northeast Normal University, China(No.20080303)the Analysis and Testing Foundation of Northeast Normal University,China
文摘Lens-like vaterite CaCO3 microrings composed of CaCO3 nanoparticles were synthesized via a microemulsion-mediated route at room temperature with ethanol and n-hexanol as co-surfactant. This process did not demand any additional energy such as heating or continuous agitation. It was the first time to use ethanol as co-surfactant in the synthesis of micro or nanomaterials. And the ethanol was believed to play an important role in the aggregation fashion of CaCO3 nanoparticles. Moreover, shuttle-shaped nanorods, hexagonal nanoplates, and rice-like nanoparticles were also fabricated by modulating the growth parameters. Additionally, the introduce of ethanol into microemulsions as co-surfactant may be generalized as a novel green route to control the structure of other functional materials.
文摘We report on an eight-channel reconfigurable optical add-drop multiplexer based on cascaded microring resonators with a high tuning power consumption and a compact footprint. Microheaters are fabricated on top of the microring resonators and can be modulated using the thermo-optic effect to achieve the reconfigurable functionality of the device. We demonstrate the reconfigurable add-drop multiplexing functionality for channel spacings of 1 O0 GHz and 50 GHz, with the centre wavelengths of the channels aligned to International Telecommunication Union grid specifications. The crosstalk for channel spacings of 100 GHz and 50 GHz are less than -22.5 dB and -15.5 dB, respectively. The average tuning efficiency is about 4.5 mW/nm, and the response speed is about 13.0 kHz.
基金supported by the Science and Technology Development of Jilin Province.China(Nos.20110320.201201078)
文摘The effects of manufacturing errors on transmission characteristics are analyzed for a polymer vertical coupling microring resonator.Calculated results show that the errors cause a shift and shape change of the transmission spectrum compared to the designed case without errors.Furthermore,accumulation and compensation for the errors is researched.In order to realize the normal filtering for the fabricated microring resonator device,some allowed errors are discussed.
基金Project supported by the National Basic Research Program of China (Grant Nos.2006CB302803 and 2011CB301701)the National Natural Science Foundation of China (Grant No.60877036)+1 种基金State Key Laboratory of Advanced Optical Communication Systems and Networks of China (Grant No.2008SH02)the Knowledge Innovation Program of Institute of Semiconductors,Chinese Academy of Sciences (Grant No.ISCAS2008T10)
文摘This paper investigated the design and the characterization of a photonic delay line based on passive cascaded silicon-on-insulator （SOI） microrings. We considered the compromise of group delay, bandwidth and insertion loss. A 3-stage double channel side-coupled integrated spaced sequence of resonator （SCISSOR） device was optimized by shifting the resonance of each microring and fabricated with electron beam lithography and dry etching. The group delay was measured to be 17 ps for non-return-to-zero signals at different bit rates and the bandwidth of 78 GHz was achieved. The experiment result agreed well with our simulation.
基金supported by the National Natural Science Foundation of China(61535012,61925505)the National Key R&D Program of China(2018YFB2201900)。
文摘A modulator is an essential building block in the integrated photonics,connecting the electrical with optical signals.The microring modulator gains much attention because of the small footprint,low drive voltage and high extinction ratio.An ultra-low V_(pp)and high-modulation-depth indium phosphide-based racetrack microring modulator is demonstrated in this paper.The proposed device mainly comprises one racetrack microring,incorporating a semiconductor amplifier,and coupling with a bus waveguide through a multimode interference coupler.Traveling wave electrodes are employed to supply bidirectional bias ports,terminating with a 50-Ω impedance.The on/off extinction ratio of the microring reaches 43.3 dB due to the delicately tuning of the gain.An 11 mV V_(pp),a maximum 42.5 dB modulation depth and a 6.6 GHz bandwidth are realized,respectively.This proposed microring modulator could enrich the functionalities and designability of the fundamental integrated devices.
