A four-stage cascaded variable optical attenuator(VOA)with a large attenuation range is presented.The VOA is based on a Mach–Zehnder interferometer(MZI)and fabricated in a silica-based planar lightwave circuit(PLC)pl...A four-stage cascaded variable optical attenuator(VOA)with a large attenuation range is presented.The VOA is based on a Mach–Zehnder interferometer(MZI)and fabricated in a silica-based planar lightwave circuit(PLC)platform.The thermo-optic effect is used to achieve intensity modulation.The measured maximum attenuation of the four-stage cascaded VOA is 88.38 d B.The chip is also tested in a quantum key distribution(QKD)system to generate signal and decoy states.The mean photon number after attenuation of the four-stage cascaded VOA is less than 0.1,which can meet the requirement of QKD.展开更多
The power consumption of a variable optical attenuator（VOA） array based on a silica planar lightwave circuit was investigated. The thermal field profile of the device was optimized using the finite-element analysis....The power consumption of a variable optical attenuator（VOA） array based on a silica planar lightwave circuit was investigated. The thermal field profile of the device was optimized using the finite-element analysis. The simulation results showed that the power consumption reduces as the depth of the heat-insulating grooves is deeper, the up-cladding is thinner,the down-cladding is thicker, and the width of the cladding ridge is narrower. The materials component and thickness of the electrodes were also optimized to guarantee the driving voltage under 5 V. The power consumption was successfully reduced to as low as 155 mW at an attenuation of 30 dB in the experiment.展开更多
Visible light variable optical attenuators（VOA） are essential devices in the application of channel power regulation and equalization in wavelength-division multiplexing cross-connect nodes in plastic optical fiber...Visible light variable optical attenuators（VOA） are essential devices in the application of channel power regulation and equalization in wavelength-division multiplexing cross-connect nodes in plastic optical fiber（POF） transmission systems.In this paper, a polymer/silica hybrid waveguide thermo–optic attenuator based on multimode interference（MMI） coupler is designed and fabricated to operate at 650 nm. The single-mode transmission condition, MMI coupler, and transition taper dimensions are optimized through the beam propagation method. Thermal analysis based on material properties provides the optimized heater placement angle. The fabricated VOA presents an attenuation of 26.5 dB with a 21-mW electrical input power at 650 nm. The rise time and fall time are 51.99 and 192 μs, respectively. The time–stability measurement results prove its working reliability.展开更多
We present a 1 × 4 Y-branch digital optical switch in which S-bend variable optical attenuators are integrated. The S-bend waveguides, which are always introduced to connect the switch and the standard fiber arra...We present a 1 × 4 Y-branch digital optical switch in which S-bend variable optical attenuators are integrated. The S-bend waveguides, which are always introduced to connect the switch and the standard fiber array, are made use of and designed as variable optical attenuators. A compact device with low crosstalk and larger branching-angle is obtained. The device is fabricated on the thermo-optic polymer materials,and the performance of the device is measured. With an applied driving power of less than 200mW, the device has a low crosstalk of less than - 35dB at a wavelength of 1.55 μm.展开更多
New techniques for controlling the amplitudes of two orthogonal linearly polarized light are presented. One is based on adjusting the DC voltage into a Mach–Zehnder modulator（MZM） to alter the amplitude of the ligh...New techniques for controlling the amplitudes of two orthogonal linearly polarized light are presented. One is based on adjusting the DC voltage into a Mach–Zehnder modulator（MZM） to alter the amplitude of the light traveling on the slow axis of a fiber into the modulator with little changes in the fast-axis light amplitude.Another is based on adjusting the input DC voltages of a dual-polarization MZM operating in the reverse direction, which enables independent control of the two input orthogonal linearly polarized light amplitudes.Experimental results demonstrate that more than 30 dB difference in slow-and fast-axis light power can be obtained by controlling an MZM input DC voltage, and over 24 dB independent power adjustment for light traveling on the slow and fast axes into a dual-polarization MZM.展开更多
A compact variable optical attenuator, covering C and L bands with over 50 dB attenuation range, is realized using a single liquid crystal cell with a tilted fused silica coating compensating the cell's small resi...A compact variable optical attenuator, covering C and L bands with over 50 dB attenuation range, is realized using a single liquid crystal cell with a tilted fused silica coating compensating the cell's small residual birefringence.展开更多
An eleetrochromic variable optical attenuator （ECVOA） was fabricated by layer-by-layer （LBL） assembly of disodium N,N-bis（p-sulfonatophenyl）naphthalenedicarboximide （Naph-SO3Na） and common cationic polymer pol...An eleetrochromic variable optical attenuator （ECVOA） was fabricated by layer-by-layer （LBL） assembly of disodium N,N-bis（p-sulfonatophenyl）naphthalenedicarboximide （Naph-SO3Na） and common cationic polymer poly（diallyldimethylammonium） chloride （PDDA）. The UV-Vis absorption spectra of the multilayer films revealed that approximately an equal amount of Naph-SO3Na was assembled in each deposition cycle. Upon one-electron reduction, multilayer films exhibited intense absorption around 452 nm and also a broad absorption band from 1200 nm to 1900 nm. Owing to the improved ionic conductivity, the optical attenuation at 1550 nm of the films showed rapid response time and reached 1.3 dB/μm within 5 s. These results indicate that layer-by-layer assembly could be an effective method for the preparation of ECVOA operating in near infrared region.展开更多
基金the National Key Research and Development Program of China(Grant No.2019YFB2203504)Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB43000000)the Natural Science Foundation of Anhui Province,China(Grant No.1908085QF274)。
文摘A four-stage cascaded variable optical attenuator(VOA)with a large attenuation range is presented.The VOA is based on a Mach–Zehnder interferometer(MZI)and fabricated in a silica-based planar lightwave circuit(PLC)platform.The thermo-optic effect is used to achieve intensity modulation.The measured maximum attenuation of the four-stage cascaded VOA is 88.38 d B.The chip is also tested in a quantum key distribution(QKD)system to generate signal and decoy states.The mean photon number after attenuation of the four-stage cascaded VOA is less than 0.1,which can meet the requirement of QKD.
基金Project supported by the National High Technology Research and Development Program of China(Grant No.2015AA016902)the National Nature Science Foundation of China(Grant Nos.61435013,61405188,and 61627820)
文摘The power consumption of a variable optical attenuator（VOA） array based on a silica planar lightwave circuit was investigated. The thermal field profile of the device was optimized using the finite-element analysis. The simulation results showed that the power consumption reduces as the depth of the heat-insulating grooves is deeper, the up-cladding is thinner,the down-cladding is thicker, and the width of the cladding ridge is narrower. The materials component and thickness of the electrodes were also optimized to guarantee the driving voltage under 5 V. The power consumption was successfully reduced to as low as 155 mW at an attenuation of 30 dB in the experiment.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61205032,61475061,61405070,61177027,61275033,and 61261130586)the Science and Technology Development Plan of Jilin Province,China(Grant No.20140519006JH)
文摘Visible light variable optical attenuators（VOA） are essential devices in the application of channel power regulation and equalization in wavelength-division multiplexing cross-connect nodes in plastic optical fiber（POF） transmission systems.In this paper, a polymer/silica hybrid waveguide thermo–optic attenuator based on multimode interference（MMI） coupler is designed and fabricated to operate at 650 nm. The single-mode transmission condition, MMI coupler, and transition taper dimensions are optimized through the beam propagation method. Thermal analysis based on material properties provides the optimized heater placement angle. The fabricated VOA presents an attenuation of 26.5 dB with a 21-mW electrical input power at 650 nm. The rise time and fall time are 51.99 and 192 μs, respectively. The time–stability measurement results prove its working reliability.
文摘We present a 1 × 4 Y-branch digital optical switch in which S-bend variable optical attenuators are integrated. The S-bend waveguides, which are always introduced to connect the switch and the standard fiber array, are made use of and designed as variable optical attenuators. A compact device with low crosstalk and larger branching-angle is obtained. The device is fabricated on the thermo-optic polymer materials,and the performance of the device is measured. With an applied driving power of less than 200mW, the device has a low crosstalk of less than - 35dB at a wavelength of 1.55 μm.
文摘New techniques for controlling the amplitudes of two orthogonal linearly polarized light are presented. One is based on adjusting the DC voltage into a Mach–Zehnder modulator（MZM） to alter the amplitude of the light traveling on the slow axis of a fiber into the modulator with little changes in the fast-axis light amplitude.Another is based on adjusting the input DC voltages of a dual-polarization MZM operating in the reverse direction, which enables independent control of the two input orthogonal linearly polarized light amplitudes.Experimental results demonstrate that more than 30 dB difference in slow-and fast-axis light power can be obtained by controlling an MZM input DC voltage, and over 24 dB independent power adjustment for light traveling on the slow and fast axes into a dual-polarization MZM.
文摘A compact variable optical attenuator, covering C and L bands with over 50 dB attenuation range, is realized using a single liquid crystal cell with a tilted fused silica coating compensating the cell's small residual birefringence.
基金supported by the National Natural Science Foundation of China(Nos.20674001,20325415, 20834001)the Research Fund for Doctoral Program of Higher Education of MOE of China(No.20060001029)
文摘An eleetrochromic variable optical attenuator （ECVOA） was fabricated by layer-by-layer （LBL） assembly of disodium N,N-bis（p-sulfonatophenyl）naphthalenedicarboximide （Naph-SO3Na） and common cationic polymer poly（diallyldimethylammonium） chloride （PDDA）. The UV-Vis absorption spectra of the multilayer films revealed that approximately an equal amount of Naph-SO3Na was assembled in each deposition cycle. Upon one-electron reduction, multilayer films exhibited intense absorption around 452 nm and also a broad absorption band from 1200 nm to 1900 nm. Owing to the improved ionic conductivity, the optical attenuation at 1550 nm of the films showed rapid response time and reached 1.3 dB/μm within 5 s. These results indicate that layer-by-layer assembly could be an effective method for the preparation of ECVOA operating in near infrared region.
