Dispersive optics quantum key distribution(DO-QKD)based on energy-time entangled photon pairs is an important QKD scheme.In DO-QKD,the arrival time of photons is used in key generation and security analysis,which woul...Dispersive optics quantum key distribution(DO-QKD)based on energy-time entangled photon pairs is an important QKD scheme.In DO-QKD,the arrival time of photons is used in key generation and security analysis,which would be greatly affected by fiber dispersion.In this work,we establish a theoretical model of the entanglement-based DO-QKD system,considering the protocol,physical processes(such as fiber transmission and single-photon detection),and the analysis of security tests.Based on this theoretical model,we investigate the influence of chromatic dispersion introduced by transmission fibers on the performance of DO-QKD.By analyzing the benefits and costs of dispersion compensation,the system performance under G.652 and G.655 optical fibers are shown,respectively.The results show that dispersion compensation is unnecessary for DO-QKD systems in campus networks and even metro networks.Whereas,it is still required in DO-QKD systems with longer fiber transmission distances.展开更多
Based on the general theory of linear Chirped Bragg fiber grating, this paper discusses some parameters including different chirped values and quasi gauss coupling function relating with the reflectivity coefficient d...Based on the general theory of linear Chirped Bragg fiber grating, this paper discusses some parameters including different chirped values and quasi gauss coupling function relating with the reflectivity coefficient dispersion compensation.The result shows that selecting larger chirped value and appropriate qusi guass coupling function can improve the dispersion compensation while ensuring high reflectivity. The concept of "figure of merit" in the microwave field is introduced to quantize the equalizing power of the dispersion compensator.展开更多
An ultrafast fiber laser system comprising two coherently combined amplifier channels is reported.Within this system,each channel incorporates a rod-type fiber power amplifier,with individual operations reaching appro...An ultrafast fiber laser system comprising two coherently combined amplifier channels is reported.Within this system,each channel incorporates a rod-type fiber power amplifier,with individual operations reaching approximately 233 W.The active-locking of these coherently combined channels,followed by compression using gratings,yields an output with a pulse energy of 504μJ and an average power of 403 W.Exceptional stability is maintained,with a 0.3%root mean square(RMS)deviation and a beam quality factor M^(2)<1.2.Notably,precise dispersion management of the front-end seed light effectively compensates for the accumulated high-order dispersion in subsequent amplification stages.This strategic approach results in a significant reduction in the final output pulse duration for the coherently combined laser beam,reducing it from 488 to 260 fs after the gratings compressor,while concurrently enhancing the energy of the primary peak from 65%to 92%.展开更多
In this paper,an efficient 8-channel 32Gbps RoF(Radio over Fiber)system incorporating Bessel Filter(8/32 RoFBF)has been demonstrated to reduce the impact of non-linear transmission effects,specifically Four-Wave Mixin...In this paper,an efficient 8-channel 32Gbps RoF(Radio over Fiber)system incorporating Bessel Filter(8/32 RoFBF)has been demonstrated to reduce the impact of non-linear transmission effects,specifically Four-Wave Mixing(FWM).The simulation results indicate that the proposed 8/32 RoF-BF system provides an optimum result w.r.t.channel spacing(75 GHz),input source power(0 dBm)and number of input channels(8).In comparison with the existing RoF system,the proposed 8/32 RoF-BF system has been validated analytically and it is found that the performance of the proposed system is in close proximity particularly in FWM sideband power reduction of the order of 4 dBm for the 8-channel 32Gbps RoF system.展开更多
The combination of Radio Frequency and Optical Fiber has resulted high capacity transmission at lower costs components and makes Radio over Fiber as a current trend of large broadband communication. In Fiber optics fi...The combination of Radio Frequency and Optical Fiber has resulted high capacity transmission at lower costs components and makes Radio over Fiber as a current trend of large broadband communication. In Fiber optics field, the use of Fiber Bragg Grating (FBG) was been proposed in recent research with different purpose of uses. However, the compensation of dispersion method of Fiber Bragg Grating (FBG) can boost significantly the system performance. This paper investigates the performance capacity improvement of adaptive Radio over Fiber system. The system design was performed using OptiSystem 7.0 software, which 10 Gb/s Non Return to Zero (NRZ) signal was launched into 50 Km Universal Mode Fiber and Fiber Bragg Grating was used as a compensator of dispersion before frequency up conversion. Therefore, the system performances were investigated by comparing the Bit Error Rate (BER) and Q-factors of Positive Intrinsic Negative (PIN) and Ultrafast Avalanche Photodiode (APD) as optical receivers. The Eye diagram analyzer showed acceptable improvement due to use of Fiber Bragg Grating as a compensator of dispersion.展开更多
For the efficient dynamic dispersion compensation, it is essential to monitor the dispersion accurately. The existing main dispersion monitoring techniques in high bit-rate optical communication systems are presented ...For the efficient dynamic dispersion compensation, it is essential to monitor the dispersion accurately. The existing main dispersion monitoring techniques in high bit-rate optical communication systems are presented as well as their operating principles and research progress. The advantages and disadvantages of these methods are analyzed and discussed.展开更多
A 10 Gbit/s recirculating system is configured with Chirped Fiber Bragg Grating (CFBG) for the dispersion compensation. For the first time, the transmission distance in the loop reaches 1000km with bit error rate of 1...A 10 Gbit/s recirculating system is configured with Chirped Fiber Bragg Grating (CFBG) for the dispersion compensation. For the first time, the transmission distance in the loop reaches 1000km with bit error rate of 10-9. The effect of the group delay ripple of the fiber grating is also investigated in the recirculating systems, and it is shown that the transmission distance is limited to 4 cycles (4× 167.1km ) in the loop with the power penalty fluctuation below 1.0dB. Thus the group delay ripple should be reduced to allow for the wavelength drift of ±5GHz.At the end of this letter, the principles are given for designing long haul recirculating systems with dispersion compensation CFBG.展开更多
High-order dispersion introduced by Gires–Tournois interferometer mirrors usually causes spectral sidebands in the nearzero dispersion region of mode-locked fiber lasers.Here,we demonstrate a sideband-free Yb-doped m...High-order dispersion introduced by Gires–Tournois interferometer mirrors usually causes spectral sidebands in the nearzero dispersion region of mode-locked fiber lasers.Here,we demonstrate a sideband-free Yb-doped mode-locked fiber laser with dispersion-compensating Gires–Tournois interferometer mirrors.Both the simulation and the experiment demonstrate that the wavelength and energy of the sidebands can be tuned by changing the transmission coefficient of the output mirror,the pump power,and the ratio of the net cavity dispersion to the net third-order dispersion in the cavity.By optimizing these three parameters,the laser can generate a sideband-free,Gaussian-shaped spectrum with a 13.56-nm bandwidth at-0.0232 ps^(2)net cavity dispersion,which corresponds to a 153-fs pulse duration.展开更多
We report the LPG pair device that can be used as a pulse duplicator or an OCDMA encoder/decoder. Due to the ring core region of dispersion compensating fiber (DCF), we can shorten the device length by a third and obt...We report the LPG pair device that can be used as a pulse duplicator or an OCDMA encoder/decoder. Due to the ring core region of dispersion compensating fiber (DCF), we can shorten the device length by a third and obtain surrounding insensitive LPG devices.展开更多
基金the National Key R&D Program of China under Grants No.2017YFA0303704 and No.2018YFB2200400Natural Science Foundation of Beijing under Grant No.Z180012National Natural Science Foundation of China under Grants No.61875101 and No.91750206.
文摘Dispersive optics quantum key distribution(DO-QKD)based on energy-time entangled photon pairs is an important QKD scheme.In DO-QKD,the arrival time of photons is used in key generation and security analysis,which would be greatly affected by fiber dispersion.In this work,we establish a theoretical model of the entanglement-based DO-QKD system,considering the protocol,physical processes(such as fiber transmission and single-photon detection),and the analysis of security tests.Based on this theoretical model,we investigate the influence of chromatic dispersion introduced by transmission fibers on the performance of DO-QKD.By analyzing the benefits and costs of dispersion compensation,the system performance under G.652 and G.655 optical fibers are shown,respectively.The results show that dispersion compensation is unnecessary for DO-QKD systems in campus networks and even metro networks.Whereas,it is still required in DO-QKD systems with longer fiber transmission distances.
文摘Based on the general theory of linear Chirped Bragg fiber grating, this paper discusses some parameters including different chirped values and quasi gauss coupling function relating with the reflectivity coefficient dispersion compensation.The result shows that selecting larger chirped value and appropriate qusi guass coupling function can improve the dispersion compensation while ensuring high reflectivity. The concept of "figure of merit" in the microwave field is introduced to quantize the equalizing power of the dispersion compensator.
基金supported by the National Natural Science Foundation of China(NSFC)(Grant Nos.9215010612021004,and 11934006)the Innovation Project of Optics Valley Laboratory(No.OVL2021ZD001),the Major Program(JD)of Hubei Province(No.203BAA015)the Cross Research Support Program of Huazhong University of Science and Technology(No.2023JCYJ041).
文摘An ultrafast fiber laser system comprising two coherently combined amplifier channels is reported.Within this system,each channel incorporates a rod-type fiber power amplifier,with individual operations reaching approximately 233 W.The active-locking of these coherently combined channels,followed by compression using gratings,yields an output with a pulse energy of 504μJ and an average power of 403 W.Exceptional stability is maintained,with a 0.3%root mean square(RMS)deviation and a beam quality factor M^(2)<1.2.Notably,precise dispersion management of the front-end seed light effectively compensates for the accumulated high-order dispersion in subsequent amplification stages.This strategic approach results in a significant reduction in the final output pulse duration for the coherently combined laser beam,reducing it from 488 to 260 fs after the gratings compressor,while concurrently enhancing the energy of the primary peak from 65%to 92%.
文摘In this paper,an efficient 8-channel 32Gbps RoF(Radio over Fiber)system incorporating Bessel Filter(8/32 RoFBF)has been demonstrated to reduce the impact of non-linear transmission effects,specifically Four-Wave Mixing(FWM).The simulation results indicate that the proposed 8/32 RoF-BF system provides an optimum result w.r.t.channel spacing(75 GHz),input source power(0 dBm)and number of input channels(8).In comparison with the existing RoF system,the proposed 8/32 RoF-BF system has been validated analytically and it is found that the performance of the proposed system is in close proximity particularly in FWM sideband power reduction of the order of 4 dBm for the 8-channel 32Gbps RoF system.
文摘The combination of Radio Frequency and Optical Fiber has resulted high capacity transmission at lower costs components and makes Radio over Fiber as a current trend of large broadband communication. In Fiber optics field, the use of Fiber Bragg Grating (FBG) was been proposed in recent research with different purpose of uses. However, the compensation of dispersion method of Fiber Bragg Grating (FBG) can boost significantly the system performance. This paper investigates the performance capacity improvement of adaptive Radio over Fiber system. The system design was performed using OptiSystem 7.0 software, which 10 Gb/s Non Return to Zero (NRZ) signal was launched into 50 Km Universal Mode Fiber and Fiber Bragg Grating was used as a compensator of dispersion before frequency up conversion. Therefore, the system performances were investigated by comparing the Bit Error Rate (BER) and Q-factors of Positive Intrinsic Negative (PIN) and Ultrafast Avalanche Photodiode (APD) as optical receivers. The Eye diagram analyzer showed acceptable improvement due to use of Fiber Bragg Grating as a compensator of dispersion.
文摘For the efficient dynamic dispersion compensation, it is essential to monitor the dispersion accurately. The existing main dispersion monitoring techniques in high bit-rate optical communication systems are presented as well as their operating principles and research progress. The advantages and disadvantages of these methods are analyzed and discussed.
基金the National 863 High Technology Development Program of China (No.2001 AA122012)
文摘A 10 Gbit/s recirculating system is configured with Chirped Fiber Bragg Grating (CFBG) for the dispersion compensation. For the first time, the transmission distance in the loop reaches 1000km with bit error rate of 10-9. The effect of the group delay ripple of the fiber grating is also investigated in the recirculating systems, and it is shown that the transmission distance is limited to 4 cycles (4× 167.1km ) in the loop with the power penalty fluctuation below 1.0dB. Thus the group delay ripple should be reduced to allow for the wavelength drift of ±5GHz.At the end of this letter, the principles are given for designing long haul recirculating systems with dispersion compensation CFBG.
基金partially supported by the National Key Research and Development Program of China(No.2021YFB3602600)the Research and Development Program in Key Areas of Guangdong Province,China(No.2020B090922004)。
文摘High-order dispersion introduced by Gires–Tournois interferometer mirrors usually causes spectral sidebands in the nearzero dispersion region of mode-locked fiber lasers.Here,we demonstrate a sideband-free Yb-doped mode-locked fiber laser with dispersion-compensating Gires–Tournois interferometer mirrors.Both the simulation and the experiment demonstrate that the wavelength and energy of the sidebands can be tuned by changing the transmission coefficient of the output mirror,the pump power,and the ratio of the net cavity dispersion to the net third-order dispersion in the cavity.By optimizing these three parameters,the laser can generate a sideband-free,Gaussian-shaped spectrum with a 13.56-nm bandwidth at-0.0232 ps^(2)net cavity dispersion,which corresponds to a 153-fs pulse duration.
文摘We report the LPG pair device that can be used as a pulse duplicator or an OCDMA encoder/decoder. Due to the ring core region of dispersion compensating fiber (DCF), we can shorten the device length by a third and obtain surrounding insensitive LPG devices.
