1 State Key Laboratory of Nuclear Physics and Technology and Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing 100871, China
2 Key Laboratory of Particle Acceleration Physics & Technology, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
3 Spallation Neutron Source Science Center, Dongguan 523803, Guangdong , China
In this paper we report a compact and robust regenerative amplifier developed as the pump laser for a high repetition rate terahertz parametric amplifier. With properly chosen pump source and carefully designed cavity, Nd∶YVO4 crystal, and laser beam collimator, a maximum output pulse energy of 480 μJ has been achieved at the repetition rate of 10 kHz. The output laser has a nearly Gaussian transverse profile and a narrow bandwidth of 0.2 nm. Long-term monitoring shows an root mean square power fluctuation of about 1%. These characteristics satisfy all requirements for high repetition rate terahertz parametric amplifier.
regenerative amplifier terahertz parametric amplifiers thermal lens 激光与光电子学进展
2022, 59(21): 2136001
强激光与粒子束
2022, 34(10): 104016
北京大学 核物理与核技术国家重点实验室，北京 100871
介绍北京大学垂直测试系统的数字化自激励环路系统，重点分析了实际测试中避免多单元（cell）超导腔模式串扰的方法以及偏离四倍频采样对信号幅度和相位的影响。该系统运行稳定可靠，可有效区分1.3 GHz 9-cell超导腔
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模与
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模，解决了多cell超导腔测试中模式串扰问题。分析了超导腔自激励环路在垂直测试中的应用，介绍了北京大学垂直测试系统的数字化自激励环路，采用上下变频方案的射频前端和包括有限脉冲响应滤波器的数字算法，系统简洁扩展性强。重点分析了实际测试中避免多cell超导腔模式串扰的方法以及偏离四倍频采样对信号幅度和相位的影响。在多种不同频率超导腔的垂直测试中该系统运行稳定可靠，可有效区分1.3 GHz 9-cell超导腔
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模与
$ 8{\rm{{\text{π}}}}/9 $![]()
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模，解决了多cell超导腔测试中模式串扰问题。
强激光与粒子束
2021, 33(2): 024001
Author Affiliations
Abstract
State Key Laboratory of Nuclear Physics and Technology and Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing 100871, China
A high repetition rate, picosecond terahertz (THz) parametric amplifier with a LiNbO3 (LN) crystal has been demonstrated in this work. At a 10 kHz repetition rate, a peak power of 200 W and an average power of 12 μW have been obtained over a wide range of around 2 THz; at a 100 kHz repetition rate, a maximum peak power of 18 W and an average power of 10.8 μW have been obtained. The parametric gain of the LN crystal was also investigated, and a modified Schwarz–Maier model was introduced to interpret the experimental results.
far infrared or terahertz nonlinear optics parametric processes parametric oscillators and amplifiers Chinese Optics Letters
2020, 18(5): 051901
1 中国科学技术大学 国家同步辐射实验室, 合肥 230026
2 北京大学 重离子物理研究所, 北京 100871
3 中国科学院 高能物理研究所, 北京 100049
北京大学高功率耦合器谐振环锻炼平台是对北京大学1.3 GHz超导加速器的耦合器进行高功率测试和锻炼的平台, 通过谐振环与信号源谐振来产生高功率。在谐振环工作过程中, 由于外界扰动会使其共振频率发生变化, 故需要对谐振环路进行频率锁定, 从而维持其与信号源的共振。将PDH（Pound-Drever-Hall）技术应用在此锻炼平台上, 用以锁定微波信号源与谐振环的频率。实验验证表明, 该PDH反馈系统能有效维持谐振环的高增益。
谐振环 PDH技术 稳频系统 RF resonant ring Pound-Drever-Hall technique frequency locking 强激光与粒子束
2018, 30(12): 123002
Author Affiliations
Abstract
Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing, China
In order to improve the precision of the laser–radio-frequency (RF) synchronization system from sub-picosecond to femtosecond (fs), a synchronization system between a picosecond laser and a 1.3 GHz RF generator has been developed based on a fiber-loop optical-microwave phase detector (FLOM-PD). Synchronization with fs-level (3.8 fs) rms jitter, integrated from 10 Hz to 1 MHz, is achieved for the first time, to the best of our knowledge, in this kind of configuration. This system will be used for the superconducting RF accelerator at Peking University.
060.5625 Radio frequency photonics 320.7090 Ultrafast lasers 350.4010 Microwaves Chinese Optics Letters
2018, 16(1): 010607
Author Affiliations
Abstract
1 Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang 621999, China
2 Key Laboratory Science and Technology on High Energy Laser, China Academy of Engineering Physics, Mianyang 621999, China
3 Gradute School, China Academy of Engineering Physics, Beijing 100088, China
4 Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
5 Institute of Applied Physics and Computational Mathematics, Beijing 100094, China
We present a diode-pumped high-energy ceramic Nd:YAG planar waveguide that is demonstrated as a record in output energy for the ceramic planar waveguide fabricated by nonaqueous tape casting and solid-state reactive sintering. Under a repetition rate of 100 Hz and a pulse width of 250 μs, a maximum output pulse energy of 327 mJ is obtained with a beam quality factor of =2.6×7.0. The corresponding peak power is 1308 W. The extraction efficiency of the system is about 56%.
140.3480 Lasers, diode-pumped 230.7390 Waveguides, planar 140.3580 Lasers, solid-state 140.3530 Lasers, neodymium Chinese Optics Letters
2016, 14(5): 051404
1 北京大学 核物理与核技术国家重点实验室, 北京 100871
2 北京北广科技股份有限公司, 北京 101312
北京大学3.5-cell直流超导(DC-SRF)光阴极注入器需要一台连续波功率20 kW的1.3 GHz微波功率源。为此北京大学和北京北广科技股份有限公司联合研制了一台由88个放大模块组成的固态微波功率放大器, 这是国内首台L波段连续波大功率固态功率源。在简要介绍这台微波功率放大器设计的基础上, 主要描述其调试过程和重要参数检测并着重讨论了全反射问题。测试结果显示这台功率源的各项参数均达到设计指标, 在输出功率20 kW时的效率为34%, 增益大于85 dB；在整个功率输出范围其增益和相移的变化分别为1.6 dB和9.5°。目前这台功率源已在DC-SRF光阴极注入器调试运行中稳定工作超过2000 h。
直流超导光阴极注入器 固态放大器 高度模块化 全反射 DC-SRF photoinjector solid state amplifier high modularity full reflection 强激光与粒子束
2016, 28(12): 125102
1 中国工程物理研究院 研究生部
2 应用电子学研究所，四川绵阳 621999
3 北京大学重离子研究所，北京 100871
4 中国工程物理研究院 应用电子学研究所，四川绵阳 621999
设计了中物院太赫兹科研装置超导加速器低电平控制系统的射频前端部分，采用了信号源8663A 与直接信号发生器板卡AD9858 结合的方案，产生射频前端所需的30.72 MHz 中频信号和1330.72 MHz 本振信号。采用AD9510 时钟板产生ADC 和DAC 采样所需的频率122.88 MHz和245.76 MHz，采样信号时间抖动仅为4 ps，由此引起的幅值采样误差和相位采样误差分别为±0.04%和±0.025%，符合设计要求。
射频前端 时钟分配 上下变频 低电平控制 超导加速器 RF front-end clock distribution up-down converter low level control superconducting accelerator 太赫兹科学与电子信息学报
2015, 13(3): 462
