设计了一种用于面向远程控制的半导体纳米激光器驱动电路, 并对其输出特性进行测试。设计的半导体纳米激光器恒流驱动电路硬件包括上电慢启动模块、恒流模块、过流保护模块三个模块, 采用恒电流模式对激光器进行控制, 确保其输出恒定光功率。整个电路由慢启动电路进行供电, 电路属于电流串联负反馈电路, 正向输入端与滑动变阻器连接。温控电路核心部分是MAX1969芯片, 其控制精度可达到0.01 ℃。测试激光器系统, 最终确定其阈值为18.5 mA, 如果保持149.5 mA的泵浦电流, 此时其输出功率为54.8 mW。该激光器温度、电流稳定性良好。

激光器驱动电路是光通信系统中发射端的重要部件, 为了适应高速电/光转换的需求, 基于28 nm互补金属氧化物半导体(CMOS)工艺, 设计了一种外调制激光器(EML)驱动电路, 整个驱动电路采用了5级级联的架构, 分别包括可变增益放大器(VGA)、两级连续时间线性均衡器(CTLE)、预放大器和输出级, 驱动电路内部采用了新型的互补放大和共源共栅结构, 驱动电路的输入为50 Gb/s的4阶脉冲振幅调制(PAM4)信号。仿真结果表明: 该驱动电路小信号带宽为27 GHz; 在12.5 GHz、0.16~0.312 VPP正弦输入下的输出摆幅为1 VPP时, 总谐波失真(THD)大小为2.21%, 电压增益范围为13.98~20.24 dB, 总功耗为340 mW。

神光Ⅱ大型固体高功率激光装置是我国激光驱动器发展历史的里程碑, 其成功研制使我国高功率固体激光工程与技术、聚变物理与基础物理研究实现了全面且本质的跨越式发展。简要概述了神光Ⅱ激光装置研制中创新发展的大量工程方案与技术手段, 举例介绍了神光Ⅱ激光装置在近20年来的高质量运行中取得的众多有国际影响力的研究成果。经多方支持和多年持续发展, 已经形成数万焦耳级纳秒激光装置、皮秒拍瓦以及飞秒拍瓦激光装置等, 这些装置是我国惯性约束核聚变、强场物理、高能量密度物理等研究领域中重要的物理实验核心平台之一。

The SG-Ⅲ laser facility (SG-Ⅲ) is the largest laser driver for inertial confinement fusion (ICF) researches in China, which has 48 beamlines and can deliver 180 kJ ultraviolet laser energy in 3 ns. In order to meet the requirements of precise physics experiments, some new functionalities need to be added to SG-Ⅲ and some intrinsic laser performances need upgrade. So at the end of SG-Ⅲ's engineering construction, the 2-year laser performance upgrade project started. This paper will introduce the newly added functionalities and the latest laser performance of SG-Ⅲ. With these function extensions and performance upgrade, SG-Ⅲ is now fully prepared for precise ICF experiments and solidly paves the way towards fusion ignition.

提出应用于激光脉冲高精度时间同步测量的技术方案。利用时间数字转换技术, 精确测量激光脉冲相对延时, 测量精度可小于10 ps(峰谷值)。为满足测量电路对脉冲宽度的要求, 设计针对短脉冲激光的电脉冲展宽模块, 可以将百皮秒量级的电脉冲展宽至纳秒量级, 引入时间抖动的均方根值小于2 ps。该测量方案实现了实时高精度时间同步测量, 可以作为时间同步反馈补偿的实时监测使用。

采用相位调制技术产生的具有一定光谱分布的相位调制脉冲可以有效抑制高功率激光驱动器中大口径光学元件的横向受激布里渊散射和满足光束匀滑需求, 但该脉冲在装置各系统传输放大过程中, 由于光谱畸变会引起幅频调制(FM-to-AM)效应, 这种效应严重影响了激光装置的输出性能及实验效果。介绍了相位调制脉冲产生原理、引起FM-to-AM效应的根本原因及因素, 综述了目前美国的国家点火装置、法国的兆焦耳装置以及我国的神光-Ⅲ主机装置在FM-to-AM效应抑制技术方面取得的重要进展。

To overcome the problem of cleanliness in the laser′s internal cavity, a glass cavity design for a Nd: glass slab amplifier was proposed, which uses UV-stop quartz glass for its main structure.The design of the main structure of the glass cavity and the sealing are optimized, and metal-coated surfaces are used to prevent light from escaping.The cleanliness of the stainless steel cavity of the slab amplifier of the SG-II-UP laser and the glass cavity of a 100 slab amplifier were compared; the cleanliness of the glass cavity was found to be 70% better than that of the stainless cavity. Further, advanced system analysis program was used to simulate the designed amplifier, with the pumping ratio of the Nd: glass in the glass cavity being increased by 8.84%.Thus, the glass cavity decreases the production of aerosols and enhances the pumping ratio of the Nd∶glass.

To overcome the problem of cleanliness in the laser′s internal cavity, a glass cavity design for a Nd: glass slab amplifier was proposed, which uses UV-stop quartz glass for its main structure.The design of the main structure of the glass cavity and the sealing are optimized, and metal-coated surfaces are used to prevent light from escaping.The cleanliness of the stainless steel cavity of the slab amplifier of the SG-II-UP laser and the glass cavity of a 100 slab amplifier were compared; the cleanliness of the glass cavity was found to be 70% better than that of the stainless cavity. Further, advanced system analysis program was used to simulate the designed amplifier, with the pumping ratio of the Nd: glass in the glass cavity being increased by 8.84%.Thus, the glass cavity decreases the production of aerosols and enhances the pumping ratio of the Nd∶glass.