Combining a Ti-diffusion periodically poled lithium niobate(PPLN)waveguide with a Sagnac interferometer,two opposite directions type-II spontaneous parametric down conversions(SPDC)occur coherently and yield a high br...Combining a Ti-diffusion periodically poled lithium niobate(PPLN)waveguide with a Sagnac interferometer,two opposite directions type-II spontaneous parametric down conversions(SPDC)occur coherently and yield a high brightness,high stability polarization entanglement source.The source produces degenerate photon pairs at 1540.4 nm with a brightness of B=(1.36±0.03)×10^(6) pairs/(s·nm·m W).We perform quantum state tomography to reconstruct the density matrix of the output state and obtain a fidelity of F=0.983±0.001.The high brightness and phase stability of our waveguide source enable a wide range of quantum information experiments operating at a low pump power as well as hold the advantage in mass production which can promote the practical applications of quantum technologies.展开更多
A 32-channel wavelength division multiplexer with 100 GHz spacing is designed and fabricated by interleaving two silicon arrayed waveguide gratings(AWGs).It has a parallel structure consisting of two silicon 16-channe...A 32-channel wavelength division multiplexer with 100 GHz spacing is designed and fabricated by interleaving two silicon arrayed waveguide gratings(AWGs).It has a parallel structure consisting of two silicon 16-channel AWGs with200 GHz spacing and a Mach-Zehnder interferometer(MZI)with 200 GHz free spectral range.The 16 channels of one silicon AWG are interleaved with those of the other AWG in spectrum,but with an identical spacing of 200 GHz.For the composed wavelength division multiplexer,the experiment results reveal 32 wavelength channels in C-band,a wavelength spacing of 100 GHz,and a channel crosstalk lower than-15 dB.展开更多
A magneto-optical(MO)metal-sandwiched multilayered structure composed of metal,MO medium and dielectric buffer layers is presented and investigated by finite-element-method-based-mode solver and perturbation theory.Th...A magneto-optical(MO)metal-sandwiched multilayered structure composed of metal,MO medium and dielectric buffer layers is presented and investigated by finite-element-method-based-mode solver and perturbation theory.The results show that this structure exhibits large nonreciprocal phase shift,strong mode confinement in the narrow buffer layers as well as very low propagation loss.The propagation length with 1dB loss is much longer than the required length of𝜌π/2 nonreciprocal phase shifts in this structure.The modal area is smaller than half of the conventional MO waveguides.This phenomenon can be used to achieve a compact plasmonic isolator based on the Mach–Zehnder interferometer.展开更多
Analytic solutions(ASs)for the spectral responses of waveguide devices with raised-cosine-apodized(RCA)gratings are presented.The waveguide devices include short-and long-period RCA-gratings,RCA-grating-based interfer...Analytic solutions(ASs)for the spectral responses of waveguide devices with raised-cosine-apodized(RCA)gratings are presented.The waveguide devices include short-and long-period RCA-gratings,RCA-grating-based interferometers as Fabry-Perot,Mach-Zehnder and Michelson interferometers.The calculations based on the analytic solutions are demonstrated and compared with those based on the transfer matrix(TM)method preferred,which has confirmed that the AS-based analysis is with enough accuracy and several thousands times the efficiency of the TM method.展开更多
In recent years, the high density plasma in the range of 10^19～ 10^20m^-3 have been operated in large or middle tokamak device in the world. A muhichannel far infrared interferometer for profile measurement of plasma...In recent years, the high density plasma in the range of 10^19～ 10^20m^-3 have been operated in large or middle tokamak device in the world. A muhichannel far infrared interferometer for profile measurement of plasma density on HL-2A divertor tokamak is being developed, however the design of the interferometer will appear many new problem in face of experimental environment of the HL-2A divertor device, such as how to make both transmission and arrangement of optics of the interferometer, the effect of electromo- tive force on device and how about the vibration etc. According to the eight windows setting on the largest flange of the device we have to design a Michelson-type FIR laser interferometer with 8 probing channels and eight concave mirrors must be attached it to the inner wall of the vacuum vessel of the device. Therefore, there are many problems should be taken into account to resolve, for example, （ 1 ） the vibration-proof consider for muhichannel interferometer and HCN laser, （2） the stabilization and reliability of the mirror frame uum vessel, the mirrors, hanging on internal wall of vachow to prevent the sputtering to （3） the vacuum seal of the windows and the design of mobile seal for the shutter to avoid the sputter coating of plasma,展开更多
We experimentally demonstrate a 16 × 16 reconfigurably nonblocking optical switch fabric using a Benes architecture. The switch fabric consists of 56 2 × 2 Mach–Zehnder interferometer based elementary switc...We experimentally demonstrate a 16 × 16 reconfigurably nonblocking optical switch fabric using a Benes architecture. The switch fabric consists of 56 2 × 2 Mach–Zehnder interferometer based elementary switches, with each integrated with a pair of waveguide microheaters. The average on-chip insertion loss is ~5.2 dB for both of the 'all-cross' and the 'all-bar' states, with a loss variation of 1 dB over all routing paths. The cross talk for all switching states is better than -30 d B. The switching time of the switch element is about 22 μs. The switching functionality is verified by transmission of a 40 Gb∕s quadrature phase-shift keying optical signal.展开更多
We demonstrate a novel high-accuracy post-fabrication trimming technique to fine-tune the phase of integrated Mach–Zehnder interferometers, enabling permanent correction of typical fabrication-based phase errors. The...We demonstrate a novel high-accuracy post-fabrication trimming technique to fine-tune the phase of integrated Mach–Zehnder interferometers, enabling permanent correction of typical fabrication-based phase errors. The effective index change of the optical mode is 0.19 in our measurement, which is approximately an order of magnitude improvement compared to previous work with similar excess optical loss. Our measurement results suggest that a phase accuracy of 0.078 rad was achievable with active feedback control.展开更多
An investigation of the properties ofa LiNbO3 photoelastic waveguide via the acceleration-induced effect is presented. A novel three-component hybrid-integrated optical accelerometer based on a Mach-Zehnder interferom...An investigation of the properties ofa LiNbO3 photoelastic waveguide via the acceleration-induced effect is presented. A novel three-component hybrid-integrated optical accelerometer based on a Mach-Zehnder interferometer with a LiNbO3 photoelastic waveguide has been designed, which is capable of detecting seismic acceleration in high-accuracy seismic exploration. The Mach-Zehnder interferometer was successfully fabricated and a lighting test used to check its quality. The frequency response characteristic of the accelerometer was measured2 The accelerometer with a resonant frequency of 3549 Hz was demonstrated to show good linear frequency responding characteristics in the range of 100-3000 Hz. The accelerometer also shows good stability and consistency. Experimental results indicate that the outputs of the on- and cross-axis are 147 and 21.3 mV, respectively.展开更多
By using poled-polymer/silicon slot waveguides in the active region and the Pockels effect of the poled-polymer,we propose a kind of Mach-Zehnder interferometer(MZI) electro-optic(EO) switch operated at 1 550 nm.Struc...By using poled-polymer/silicon slot waveguides in the active region and the Pockels effect of the poled-polymer,we propose a kind of Mach-Zehnder interferometer(MZI) electro-optic(EO) switch operated at 1 550 nm.Structural parameters are optimized for realizing normal switching function.Dependencies of switching characteristics on the slot waveguide parameters are investigated.For the silicon strip with dimension of 170 nm×300 nm,as the slot width varies from 50 nm to 100 nm,the switching voltage can be as low as 1.0 V with active region length of only 0.17–0.35 mm,and the length of the whole device is only about 770–950 μm.The voltage-length product of this switching structure is only 0.17–0.35 V·mm,and it is at least 19–40 times smaller than that of the traditional polymer MZI EO switch,which is 6.69 V·mm.Compared with our previously reported MZI EO switches,this switch exhibits some superior characteristics,including low switching voltage,compact device size and small wavelength dependency.展开更多
基金Project supported by the National Key R&D Program of China(Grant Nos.2022YFF0712800 and 2019YFA0308700)。
文摘Combining a Ti-diffusion periodically poled lithium niobate(PPLN)waveguide with a Sagnac interferometer,two opposite directions type-II spontaneous parametric down conversions(SPDC)occur coherently and yield a high brightness,high stability polarization entanglement source.The source produces degenerate photon pairs at 1540.4 nm with a brightness of B=(1.36±0.03)×10^(6) pairs/(s·nm·m W).We perform quantum state tomography to reconstruct the density matrix of the output state and obtain a fidelity of F=0.983±0.001.The high brightness and phase stability of our waveguide source enable a wide range of quantum information experiments operating at a low pump power as well as hold the advantage in mass production which can promote the practical applications of quantum technologies.
基金Project supported by the National Key Research and Development Program of China(Grant No.2019YFB2203600)。
文摘A 32-channel wavelength division multiplexer with 100 GHz spacing is designed and fabricated by interleaving two silicon arrayed waveguide gratings(AWGs).It has a parallel structure consisting of two silicon 16-channel AWGs with200 GHz spacing and a Mach-Zehnder interferometer(MZI)with 200 GHz free spectral range.The 16 channels of one silicon AWG are interleaved with those of the other AWG in spectrum,but with an identical spacing of 200 GHz.For the composed wavelength division multiplexer,the experiment results reveal 32 wavelength channels in C-band,a wavelength spacing of 100 GHz,and a channel crosstalk lower than-15 dB.
基金Supported by the National Natural Science Foundation of China(No 61177055)the National Basic Research Program of China(No 2013CB632105)the Fujian-Provincial Education Department Foundation of China(JK2013053).
文摘A magneto-optical(MO)metal-sandwiched multilayered structure composed of metal,MO medium and dielectric buffer layers is presented and investigated by finite-element-method-based-mode solver and perturbation theory.The results show that this structure exhibits large nonreciprocal phase shift,strong mode confinement in the narrow buffer layers as well as very low propagation loss.The propagation length with 1dB loss is much longer than the required length of𝜌π/2 nonreciprocal phase shifts in this structure.The modal area is smaller than half of the conventional MO waveguides.This phenomenon can be used to achieve a compact plasmonic isolator based on the Mach–Zehnder interferometer.
文摘Analytic solutions(ASs)for the spectral responses of waveguide devices with raised-cosine-apodized(RCA)gratings are presented.The waveguide devices include short-and long-period RCA-gratings,RCA-grating-based interferometers as Fabry-Perot,Mach-Zehnder and Michelson interferometers.The calculations based on the analytic solutions are demonstrated and compared with those based on the transfer matrix(TM)method preferred,which has confirmed that the AS-based analysis is with enough accuracy and several thousands times the efficiency of the TM method.
文摘In recent years, the high density plasma in the range of 10^19～ 10^20m^-3 have been operated in large or middle tokamak device in the world. A muhichannel far infrared interferometer for profile measurement of plasma density on HL-2A divertor tokamak is being developed, however the design of the interferometer will appear many new problem in face of experimental environment of the HL-2A divertor device, such as how to make both transmission and arrangement of optics of the interferometer, the effect of electromo- tive force on device and how about the vibration etc. According to the eight windows setting on the largest flange of the device we have to design a Michelson-type FIR laser interferometer with 8 probing channels and eight concave mirrors must be attached it to the inner wall of the vacuum vessel of the device. Therefore, there are many problems should be taken into account to resolve, for example, （ 1 ） the vibration-proof consider for muhichannel interferometer and HCN laser, （2） the stabilization and reliability of the mirror frame uum vessel, the mirrors, hanging on internal wall of vachow to prevent the sputtering to （3） the vacuum seal of the windows and the design of mobile seal for the shutter to avoid the sputter coating of plasma,
基金863 Program(2013AA01442)National Natural Science Foundation of China(NSFC)(61422508,61535006)Shanghai Rising-Star Program(14QA1402600)
文摘We experimentally demonstrate a 16 × 16 reconfigurably nonblocking optical switch fabric using a Benes architecture. The switch fabric consists of 56 2 × 2 Mach–Zehnder interferometer based elementary switches, with each integrated with a pair of waveguide microheaters. The average on-chip insertion loss is ~5.2 dB for both of the 'all-cross' and the 'all-bar' states, with a loss variation of 1 dB over all routing paths. The cross talk for all switching states is better than -30 d B. The switching time of the switch element is about 22 μs. The switching functionality is verified by transmission of a 40 Gb∕s quadrature phase-shift keying optical signal.
基金Engineering and Physical Sciences Research Council(EPSRC)(EP/L00044X/1,EP/M022757/1)Wolfson FoundationRoyal Society
文摘We demonstrate a novel high-accuracy post-fabrication trimming technique to fine-tune the phase of integrated Mach–Zehnder interferometers, enabling permanent correction of typical fabrication-based phase errors. The effective index change of the optical mode is 0.19 in our measurement, which is approximately an order of magnitude improvement compared to previous work with similar excess optical loss. Our measurement results suggest that a phase accuracy of 0.078 rad was achievable with active feedback control.
基金supported by the National Natural Science Foundation of China (No. 40774067)the Applied Basic Research Program of Sichuan Province, China (No. 07JY029-135)
文摘An investigation of the properties ofa LiNbO3 photoelastic waveguide via the acceleration-induced effect is presented. A novel three-component hybrid-integrated optical accelerometer based on a Mach-Zehnder interferometer with a LiNbO3 photoelastic waveguide has been designed, which is capable of detecting seismic acceleration in high-accuracy seismic exploration. The Mach-Zehnder interferometer was successfully fabricated and a lighting test used to check its quality. The frequency response characteristic of the accelerometer was measured2 The accelerometer with a resonant frequency of 3549 Hz was demonstrated to show good linear frequency responding characteristics in the range of 100-3000 Hz. The accelerometer also shows good stability and consistency. Experimental results indicate that the outputs of the on- and cross-axis are 147 and 21.3 mV, respectively.
基金supported by the National Natural Science Foundation of China(Nos.61107021,61177027 and 61077074)the Ministry of Education of China(Nos.20110061120052 and 20120061130008)the Science and Technology Department of Jilin Province of China(No.20130522161JH)
文摘By using poled-polymer/silicon slot waveguides in the active region and the Pockels effect of the poled-polymer,we propose a kind of Mach-Zehnder interferometer(MZI) electro-optic(EO) switch operated at 1 550 nm.Structural parameters are optimized for realizing normal switching function.Dependencies of switching characteristics on the slot waveguide parameters are investigated.For the silicon strip with dimension of 170 nm×300 nm,as the slot width varies from 50 nm to 100 nm,the switching voltage can be as low as 1.0 V with active region length of only 0.17–0.35 mm,and the length of the whole device is only about 770–950 μm.The voltage-length product of this switching structure is only 0.17–0.35 V·mm,and it is at least 19–40 times smaller than that of the traditional polymer MZI EO switch,which is 6.69 V·mm.Compared with our previously reported MZI EO switches,this switch exhibits some superior characteristics,including low switching voltage,compact device size and small wavelength dependency.
