A 10 Gbit/s burst-mode preamplifier is designed for passive optical networks （PONs）. To achieve a high dynamic range and fast response, the circuit is DC coupled, and a feed-back type peak detector is designed to pe...A 10 Gbit/s burst-mode preamplifier is designed for passive optical networks （PONs）. To achieve a high dynamic range and fast response, the circuit is DC coupled, and a feed-back type peak detector is designed to perform auto-gaincontrol and threshold extraction. Regulated cascade （RGC） architecture is exploited as the input stage to reduce the input impedance of the circuit and isolate the large parasitic capacitance including the photodiode capacitance from the determination pole, thus increasing the bandwidth. This preamplifier is implemented using the low-cost 0. 13 ixm CMOS technology. The die area is 425 μm × 475 μm and the total power dissipation is 23.4 mW. The test results indicate that the preamplifier can work at a speed from 1.25 to 10.312 5 Gbit/s, providing a high transimpedance gain of 64.0 dBΩ and a low gain of 54. 6 dBl2 with a dynamic input range of over 22.9 dB. The equivalent input noise current is 23. 4 pA/ Hz1/2. The proposed burst amplifier satisfies related specifications defined in 10G-EPON and XG-PON standards.展开更多
The influence of the picosecond(ps) pulsed burst with a nanosecond scale of temporal separation(50 ns) on filamentary traces in sapphire substrate is investigated. The spatiotemporal evolution of the filamentary plasm...The influence of the picosecond(ps) pulsed burst with a nanosecond scale of temporal separation(50 ns) on filamentary traces in sapphire substrate is investigated. The spatiotemporal evolution of the filamentary plasma string induced by sub-pulses of the burst-mode is revealed according to the analysis of the instantaneous photoluminescence images. Due to the presence of residual plasma, the energy loss of sub-pulse during the balancing of self-focusing effect is reduced, and thus refreshes the plasma via refocusing. The refreshed plasma peak generated by the subsequent subpulse appears at relatively low density positions in the formed filamentary plasma string, which results in more uniform densities and less spatial overlap among the plasma peaks. The continuity and uniformity of the filamentary trace in sapphire are enhanced by the burst-mode. Besides, the burst filamentary propagation can also remain effective when the sub-pulse energy is below the self-focusing threshold. Based on this uniform and precise energy propagation mode, the feasibility of its use for the laser lift-off(LLO) process is verified.展开更多
This paper presents an innovative switched-mode auto gain control （AGC） circuit with internally created reset module for DC-10Mb/s burst-mode unbalanced （BMU） optical data transmission. Conventional AGC circuit is...This paper presents an innovative switched-mode auto gain control （AGC） circuit with internally created reset module for DC-10Mb/s burst-mode unbalanced （BMU） optical data transmission. Conventional AGC circuit is inappropriate for BMU data transmission because it is based on average level detection and requires considerable time to settle on a predefined gain. Therefore, we adopt a fast switched-mode AGC based on peak level detection. After the gain is adjusted, the peak level detectors need to re-detect the peak level of the input signal. Thus, we develop an internally created reset module. This AGC with reset module exhibits a fast operation and achieves an adjusted stable gain within one-bit, avoiding any bit loss up to 10Mb/s data rate. During power-up, the peak level detectors possibly hold an uncertain level resulting in the bit-errors. We propose a power-up reset circuit to solve this problem. Designed in a 0.5μm CMOS technology, the circuit achieves an optical sensitivity of better than -30dBm and a wide dynamic range of over 30dB with a power dissipation of only 30 mW from a 5V supply.展开更多
We demonstrate a compact periodically poled MgO-doped lithium niobate（MgO：PPLN）-based optical parametric oscillator（OPO） quasi-synchronously pumped by a fiber laser system with burst-mode operation.The pump sourc...We demonstrate a compact periodically poled MgO-doped lithium niobate（MgO：PPLN）-based optical parametric oscillator（OPO） quasi-synchronously pumped by a fiber laser system with burst-mode operation.The pump source is a peak-power-selectable pulse-multiplied picosecond Yb fiber laser.The chirped pulses from a figure of eight-cavity modelocked fiber laser seed are narrowed to a duration of less than 50 ps using an FBG reflector and a circulator.The narrowed pulses are directed to pass through a pulse multiplier and to form pulse bunches,each of which is composed of 13 subpulses.The obtained pulse bunches are amplified by two-stage fiber pre-amplifiers：one-stage is core-pumped and the other is cladding-pumped.A fiberized acousto-optic modulator is inserted to control the pulse repetition rate（PRR） of the pulse bunches before they are power-amplified in the final amplifier stage with a large mode area（LMA） PM Yb-doped fiber.The maximum average powers from the final amplifier are 85 W,60 W,and 45 W,respectively,corresponding to the PRR of2.72 MHz,1.36 MHz,and 0.68 MHz.The amplified pulses are directed to pump an MgO：PPLN-based optical parametric oscillator（OPO）.A maximum peak power at 3.45 μm is obtained approximately to be 8.4 kW.Detailed performance characteristics are presented.展开更多
We demonstrate a high-peak-power master oscillator power amplifier burst-mode laser system that generates microsecond burst duration pulses at 355 nm with a GHz-adjustable intra-burst pulse frequency.In the fiber seed...We demonstrate a high-peak-power master oscillator power amplifier burst-mode laser system that generates microsecond burst duration pulses at 355 nm with a GHz-adjustable intra-burst pulse frequency.In the fiber seed,a highbandwidth electro-optic modulator is employed to modulate a continuous-wave(CW)laser into a pulse train at GHz frequency.To acquire a microsecond rectangular burst pulse envelope,two acousto-optic modulators are used to chop the CW pulse train and generate a pre-compensation burst envelope.A three-stage neodymium-doped yttrium aluminum garnet amplifier boosts the burst-mode fiber seed’s burst energy of 1.65 J at 1064 nm.To achieve a high-power ultraviolet(UV)burst-mode laser,sum frequency generation in a LiB_(3)O_(5)crystal is employed to convert the wavelength,achieving over 300 kW of peak power at 1.15μs/10 Hz.The intra-burst pulse frequency of the UV burst laser can be adjustable from 1 to 10 GHz with a sinusoidal waveform.To the best of our knowledge,this paper represents the highest reported microsecond UV burst-mode laser in terms of output energy and peak power with the GHz-adjustable intra-burst frequency.The high-power microsecond UV burst-mode pulse laser can be directly used as a light-driven source in large-bandwidth/high-power microwave photonic systems,providing a long pulse width and high peak power laser while significantly improving the system’s multi-parameter adjustment capability and adaptability.展开更多
Narrowband microwave generation with tuneable frequency is demonstrated by illuminating a photoconductive semiconductor switch(PCSS)with a burst-mode fibre laser.The whole system is composed of a high-power linearly p...Narrowband microwave generation with tuneable frequency is demonstrated by illuminating a photoconductive semiconductor switch(PCSS)with a burst-mode fibre laser.The whole system is composed of a high-power linearly polarized burst-mode pulsed fibre laser and a linear-state PCSS.To obtain a high-performance microwave signal,a desired envelope of burst is necessary and a pulse pre-compensation technique is adopted to avoid envelope distortion induced by the gain-saturation effect.Resulting from the technique,homogenous peak power distribution in each burst is ensured.The maximum energy of the laser burst pulse reaches 200μJ with a burst duration of 100 ns at the average power of 10 W,corresponding to a peak power of 4 kW.When the PCSS is illuminated by the burst-mode fibre laser,narrowband microwave generation with tuneable frequency(0.80-1.12 GHz)is obtained with a power up to 300 W.To the best of the authors’knowledge,it is the first demonstration of frequency-tuneable narrowband microwave generation based on a fibre laser.The high-power burst-mode fibre laser reported here has great potential for generating high-power arbitrary microwave signals for a great deal of applicable demands such as smart adaptive radar and intelligent high-power microwave systems.展开更多
We report a Yb-doped all-fiber laser system generating burst-mode pulses with high energy and high peak power at a GHz intra-burst repetition rate.To acquire the uniform burst envelope,a double-pre-compensation struct...We report a Yb-doped all-fiber laser system generating burst-mode pulses with high energy and high peak power at a GHz intra-burst repetition rate.To acquire the uniform burst envelope,a double-pre-compensation structure with an arbitrary waveform laser diode driver and an acoustic optical modulator is utilized for the first time.The synchronous pumping is utilized for the system to reduce the burst repetition rate to 100 Hz and suppress the amplified spontaneous emission effect.By adjusting the gain of every stage,uniform envelopes with different output energies can be easily obtained.The intra-burst repetition rate can be tuned from 0.5 to 10 GHz actively modulated by an electro-optic modulator.Optimized by timing control of eight channels of analog signal and amplified by seven stages of Yb-doped fiber amplifier,the pulse energy achieves 13.3 mJ at 0.5 ns intra-burst pulse duration,and the maximum peak power reaches approximately3.6 MW at 48 ps intra-burst pulse duration.To the best of our knowledge,for reported burst-mode all-fiber lasers,this is a record for output energy and peak power with nanosecond-level burst duration,and the widest tuning range of the intra-burst repetition rate.In particular,this flexibly tunable burst-mode laser system can be directly applied to generate high-power frequency-tunable microwaves.展开更多
We introduce a gated oscillator based on XONR/XOR cells and illustrate its working process. A halfrate BM-CDR circuit based on the proposed oscillator is designed, and the design is implemented in SMIC 0.13 μm CMOS t...We introduce a gated oscillator based on XONR/XOR cells and illustrate its working process. A halfrate BM-CDR circuit based on the proposed oscillator is designed, and the design is implemented in SMIC 0.13 μm CMOS technology occupying an area of 675 ×25 μm2. The measured results show that this circuit can recover clock and data from each 10 Gbit/s burst-mode data packet within 5 bits, and the recovered data pass eye-mask test defined in IEEE standard 802.3av.展开更多
This paper introduces a novel fiber-based picosecond burst-mode laser system capable of operating at high power and high repetition rates. A pulse-circulating fiber ring was developed as a burst generator, achieving a...This paper introduces a novel fiber-based picosecond burst-mode laser system capable of operating at high power and high repetition rates. A pulse-circulating fiber ring was developed as a burst generator, achieving an intra-burst repetition rate of 469 MHz without the need for a high-repetition-rate seed source. This design also allows for flexible adjustment of the number of sub-pulses, burst repetition rate and burst shape. In addition, a master oscillator power amplifier was employed to analyze the amplification characteristics of bursts. The system demonstrated a maximum average power of 606 W, with a measured sub-pulse duration of 62 ps and the highest sub-pulse peak power of 980 kW. To the best of our knowledge, this marks the highest average power obtained in burst-mode ultrafast lasers. Such a laser system holds potential for applications in precision manufacturing, high-speed imaging, high-precision ranging and other diverse domains.展开更多
在露天矿山向地下延伸开采工程实践中,探究充填体−岩石(Cemented Paste Backfill-Rock,CPB-R)组合体结构的力学特征与变形破坏规律,对保证地下采场稳定性和煤矿岩爆灾害防治具有特殊重要性。采用PFC^(2D)软件的刚性块体弹簧网络方法(Rig...在露天矿山向地下延伸开采工程实践中,探究充填体−岩石(Cemented Paste Backfill-Rock,CPB-R)组合体结构的力学特征与变形破坏规律,对保证地下采场稳定性和煤矿岩爆灾害防治具有特殊重要性。采用PFC^(2D)软件的刚性块体弹簧网络方法(Rigid Body Spring Network,RBSN)对单轴压缩条件下含不同界面倾角的CPB-R组合体结构的破坏行为进行了数值模拟研究,从宏细观角度探究了不同界面倾角对CPB-R组合体的强度特征、破坏模式和声发射特征的影响规律,并开展室内单轴压缩试验对数值模拟结果进行了验证和对比分析。研究结果表明:CPB-R组合体的强度随界面倾角增大呈现出先增大后减小的“U”形变化,且在倾角达到60°左右时具有最小的峰值强度;界面倾角超过30°后,应力应变曲线屈服阶段削弱,脆性特征显著增加,随着界面倾角的增大,CPB-R组合体的破坏模式呈现出“Y”形失效向界面滑移失效转变,再向混合失效转变的演变趋势,极限承载力呈现由充填体控制向界面控制转变,再转变为由岩石控制的演变趋势;随着CPB-R组合体界面倾角的增大,界面破坏程度不断提高,界面破损会阻止界面的进一步滑移(界面倾角<60°)并导致张拉破坏的出现;岩爆指数(K_(E))在充填体与岩石的弹性模量比增大过程中先降低后升高,控制充填体与岩石的弹性模量比在0.4~0.5时可以有效地降低岩爆的风险。展开更多
基金The Key Technology Research and Development Program of Jiangsu Province ( No. BE2008128)
文摘A 10 Gbit/s burst-mode preamplifier is designed for passive optical networks （PONs）. To achieve a high dynamic range and fast response, the circuit is DC coupled, and a feed-back type peak detector is designed to perform auto-gaincontrol and threshold extraction. Regulated cascade （RGC） architecture is exploited as the input stage to reduce the input impedance of the circuit and isolate the large parasitic capacitance including the photodiode capacitance from the determination pole, thus increasing the bandwidth. This preamplifier is implemented using the low-cost 0. 13 ixm CMOS technology. The die area is 425 μm × 475 μm and the total power dissipation is 23.4 mW. The test results indicate that the preamplifier can work at a speed from 1.25 to 10.312 5 Gbit/s, providing a high transimpedance gain of 64.0 dBΩ and a low gain of 54. 6 dBl2 with a dynamic input range of over 22.9 dB. The equivalent input noise current is 23. 4 pA/ Hz1/2. The proposed burst amplifier satisfies related specifications defined in 10G-EPON and XG-PON standards.
基金Project(51975017) supported by the National Natural Science Foundation of ChinaProject(KZ202110005012) supported by the Scientific Research Project of Beijing Educational Committee+1 种基金ChinaProject(2018YFB1107500) supported by the National Key R&D Program of China。
文摘The influence of the picosecond(ps) pulsed burst with a nanosecond scale of temporal separation(50 ns) on filamentary traces in sapphire substrate is investigated. The spatiotemporal evolution of the filamentary plasma string induced by sub-pulses of the burst-mode is revealed according to the analysis of the instantaneous photoluminescence images. Due to the presence of residual plasma, the energy loss of sub-pulse during the balancing of self-focusing effect is reduced, and thus refreshes the plasma via refocusing. The refreshed plasma peak generated by the subsequent subpulse appears at relatively low density positions in the formed filamentary plasma string, which results in more uniform densities and less spatial overlap among the plasma peaks. The continuity and uniformity of the filamentary trace in sapphire are enhanced by the burst-mode. Besides, the burst filamentary propagation can also remain effective when the sub-pulse energy is below the self-focusing threshold. Based on this uniform and precise energy propagation mode, the feasibility of its use for the laser lift-off(LLO) process is verified.
基金Supported by the Natural Science Foundation of Jiangsu Province （ BK2010411 ） and the National International Cooperation Project of China-Korea （2011DFA11310）.
文摘This paper presents an innovative switched-mode auto gain control （AGC） circuit with internally created reset module for DC-10Mb/s burst-mode unbalanced （BMU） optical data transmission. Conventional AGC circuit is inappropriate for BMU data transmission because it is based on average level detection and requires considerable time to settle on a predefined gain. Therefore, we adopt a fast switched-mode AGC based on peak level detection. After the gain is adjusted, the peak level detectors need to re-detect the peak level of the input signal. Thus, we develop an internally created reset module. This AGC with reset module exhibits a fast operation and achieves an adjusted stable gain within one-bit, avoiding any bit loss up to 10Mb/s data rate. During power-up, the peak level detectors possibly hold an uncertain level resulting in the bit-errors. We propose a power-up reset circuit to solve this problem. Designed in a 0.5μm CMOS technology, the circuit achieves an optical sensitivity of better than -30dBm and a wide dynamic range of over 30dB with a power dissipation of only 30 mW from a 5V supply.
基金supported by the National Natural Science Foundation of China(Grant No.61078015)the National Basic Research Program of China(Grant No.2011CB311803)
文摘We demonstrate a compact periodically poled MgO-doped lithium niobate（MgO：PPLN）-based optical parametric oscillator（OPO） quasi-synchronously pumped by a fiber laser system with burst-mode operation.The pump source is a peak-power-selectable pulse-multiplied picosecond Yb fiber laser.The chirped pulses from a figure of eight-cavity modelocked fiber laser seed are narrowed to a duration of less than 50 ps using an FBG reflector and a circulator.The narrowed pulses are directed to pass through a pulse multiplier and to form pulse bunches,each of which is composed of 13 subpulses.The obtained pulse bunches are amplified by two-stage fiber pre-amplifiers：one-stage is core-pumped and the other is cladding-pumped.A fiberized acousto-optic modulator is inserted to control the pulse repetition rate（PRR） of the pulse bunches before they are power-amplified in the final amplifier stage with a large mode area（LMA） PM Yb-doped fiber.The maximum average powers from the final amplifier are 85 W,60 W,and 45 W,respectively,corresponding to the PRR of2.72 MHz,1.36 MHz,and 0.68 MHz.The amplified pulses are directed to pump an MgO：PPLN-based optical parametric oscillator（OPO）.A maximum peak power at 3.45 μm is obtained approximately to be 8.4 kW.Detailed performance characteristics are presented.
基金supported by the National Natural Science Foundation of China(Grant Nos.62071477 and 62101577)the Postgraduate Scientific Research Innovation Project of Hunan Province(Grant No.QL20230011).
文摘We demonstrate a high-peak-power master oscillator power amplifier burst-mode laser system that generates microsecond burst duration pulses at 355 nm with a GHz-adjustable intra-burst pulse frequency.In the fiber seed,a highbandwidth electro-optic modulator is employed to modulate a continuous-wave(CW)laser into a pulse train at GHz frequency.To acquire a microsecond rectangular burst pulse envelope,two acousto-optic modulators are used to chop the CW pulse train and generate a pre-compensation burst envelope.A three-stage neodymium-doped yttrium aluminum garnet amplifier boosts the burst-mode fiber seed’s burst energy of 1.65 J at 1064 nm.To achieve a high-power ultraviolet(UV)burst-mode laser,sum frequency generation in a LiB_(3)O_(5)crystal is employed to convert the wavelength,achieving over 300 kW of peak power at 1.15μs/10 Hz.The intra-burst pulse frequency of the UV burst laser can be adjustable from 1 to 10 GHz with a sinusoidal waveform.To the best of our knowledge,this paper represents the highest reported microsecond UV burst-mode laser in terms of output energy and peak power with the GHz-adjustable intra-burst frequency.The high-power microsecond UV burst-mode pulse laser can be directly used as a light-driven source in large-bandwidth/high-power microwave photonic systems,providing a long pulse width and high peak power laser while significantly improving the system’s multi-parameter adjustment capability and adaptability.
文摘Narrowband microwave generation with tuneable frequency is demonstrated by illuminating a photoconductive semiconductor switch(PCSS)with a burst-mode fibre laser.The whole system is composed of a high-power linearly polarized burst-mode pulsed fibre laser and a linear-state PCSS.To obtain a high-performance microwave signal,a desired envelope of burst is necessary and a pulse pre-compensation technique is adopted to avoid envelope distortion induced by the gain-saturation effect.Resulting from the technique,homogenous peak power distribution in each burst is ensured.The maximum energy of the laser burst pulse reaches 200μJ with a burst duration of 100 ns at the average power of 10 W,corresponding to a peak power of 4 kW.When the PCSS is illuminated by the burst-mode fibre laser,narrowband microwave generation with tuneable frequency(0.80-1.12 GHz)is obtained with a power up to 300 W.To the best of the authors’knowledge,it is the first demonstration of frequency-tuneable narrowband microwave generation based on a fibre laser.The high-power burst-mode fibre laser reported here has great potential for generating high-power arbitrary microwave signals for a great deal of applicable demands such as smart adaptive radar and intelligent high-power microwave systems.
基金supported by the National Natural Science Foundation of China(No.62205374)the Research Funds of the State Key Laboratory of Pulsed Power Laser Technology,China(Nos.SKL2021KF07 and SKL2020ZR06)
文摘We report a Yb-doped all-fiber laser system generating burst-mode pulses with high energy and high peak power at a GHz intra-burst repetition rate.To acquire the uniform burst envelope,a double-pre-compensation structure with an arbitrary waveform laser diode driver and an acoustic optical modulator is utilized for the first time.The synchronous pumping is utilized for the system to reduce the burst repetition rate to 100 Hz and suppress the amplified spontaneous emission effect.By adjusting the gain of every stage,uniform envelopes with different output energies can be easily obtained.The intra-burst repetition rate can be tuned from 0.5 to 10 GHz actively modulated by an electro-optic modulator.Optimized by timing control of eight channels of analog signal and amplified by seven stages of Yb-doped fiber amplifier,the pulse energy achieves 13.3 mJ at 0.5 ns intra-burst pulse duration,and the maximum peak power reaches approximately3.6 MW at 48 ps intra-burst pulse duration.To the best of our knowledge,for reported burst-mode all-fiber lasers,this is a record for output energy and peak power with nanosecond-level burst duration,and the widest tuning range of the intra-burst repetition rate.In particular,this flexibly tunable burst-mode laser system can be directly applied to generate high-power frequency-tunable microwaves.
基金supported by the Key Technology Research and Development Program of Jiangsu Province,Industry Part,China(No.BE2008128)
文摘We introduce a gated oscillator based on XONR/XOR cells and illustrate its working process. A halfrate BM-CDR circuit based on the proposed oscillator is designed, and the design is implemented in SMIC 0.13 μm CMOS technology occupying an area of 675 ×25 μm2. The measured results show that this circuit can recover clock and data from each 10 Gbit/s burst-mode data packet within 5 bits, and the recovered data pass eye-mask test defined in IEEE standard 802.3av.
基金financially supported by the CAS Project for Young Scientists in Basic Research(No.YSBR065)the National Natural Science Foundation of China(Nos.62225507,62175230,62175232 and 62275244)the National Key R&D Program of China(No.2022YFB3607800)
文摘This paper introduces a novel fiber-based picosecond burst-mode laser system capable of operating at high power and high repetition rates. A pulse-circulating fiber ring was developed as a burst generator, achieving an intra-burst repetition rate of 469 MHz without the need for a high-repetition-rate seed source. This design also allows for flexible adjustment of the number of sub-pulses, burst repetition rate and burst shape. In addition, a master oscillator power amplifier was employed to analyze the amplification characteristics of bursts. The system demonstrated a maximum average power of 606 W, with a measured sub-pulse duration of 62 ps and the highest sub-pulse peak power of 980 kW. To the best of our knowledge, this marks the highest average power obtained in burst-mode ultrafast lasers. Such a laser system holds potential for applications in precision manufacturing, high-speed imaging, high-precision ranging and other diverse domains.
文摘在露天矿山向地下延伸开采工程实践中,探究充填体−岩石(Cemented Paste Backfill-Rock,CPB-R)组合体结构的力学特征与变形破坏规律,对保证地下采场稳定性和煤矿岩爆灾害防治具有特殊重要性。采用PFC^(2D)软件的刚性块体弹簧网络方法(Rigid Body Spring Network,RBSN)对单轴压缩条件下含不同界面倾角的CPB-R组合体结构的破坏行为进行了数值模拟研究,从宏细观角度探究了不同界面倾角对CPB-R组合体的强度特征、破坏模式和声发射特征的影响规律,并开展室内单轴压缩试验对数值模拟结果进行了验证和对比分析。研究结果表明:CPB-R组合体的强度随界面倾角增大呈现出先增大后减小的“U”形变化,且在倾角达到60°左右时具有最小的峰值强度;界面倾角超过30°后,应力应变曲线屈服阶段削弱,脆性特征显著增加,随着界面倾角的增大,CPB-R组合体的破坏模式呈现出“Y”形失效向界面滑移失效转变,再向混合失效转变的演变趋势,极限承载力呈现由充填体控制向界面控制转变,再转变为由岩石控制的演变趋势;随着CPB-R组合体界面倾角的增大,界面破坏程度不断提高,界面破损会阻止界面的进一步滑移(界面倾角<60°)并导致张拉破坏的出现;岩爆指数(K_(E))在充填体与岩石的弹性模量比增大过程中先降低后升高,控制充填体与岩石的弹性模量比在0.4~0.5时可以有效地降低岩爆的风险。
