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摘要:
光束质量是衡量 器应用性能的重要指标之一,面向远距离光电对抗应用场景,本文开展了非链式脉冲氟化氘(DF) 器非稳腔设计和光束质量提升技术研究。设计了3组不同放大倍率的正分支虚共焦非稳腔,搭建了凸面腔镜横向和轴向两种支撑结构的非稳腔实验装置,其中横向支撑结构内置循环水冷却通道。以86.5%环围能量定义 光斑大小,选用
β 因子评价 光束质量,比较两种支撑方式下的输出能量和光束质量。研究发现:相同条件下,轴向支撑结构的非稳腔输出能量较横向支撑结构高6%,但远场发散角较横向支撑大9%;水冷横向支撑结构虽存在部分能量遮挡,但其较好的热稳定性显著提升了 光束质量。在M =2.25的横向支撑内腔式非稳腔条件下获得了光束质量因子β =1.83、发散角θ 0.865=0.63 mrad的 光束。该条件下的 单脉冲能量为2.34 J, 脉宽为88.2 ns,峰值功率达到26.5 MW。Abstract:Laser beam quality is one of the key indicators to measure the application performance of laser. To meet the application requirements of long-distance optoelectronic countermeasures, we cany out the research on the design of unstable resonators and beam quality improvement techniques for non-chain pulsed deuterium fluoride (DF) lasers. Three sets of positive branch virtual confocal unstable resonators with different magnifications are designed. An inner cavity unstable resonator with two support structures of convex mirror, transverse support and longitudinal support, are constructed. The transverse support structure is equipped with a circulating water-cooling channel. Using 86.5% surrounding energy to define laser beam diameter, the laser beam quality is evaluated with beam quality factor
β , and the energy and beam divergence for two support types of convex mirrors are compared. It can be found that, under the same conditions, the laser energy of unstable resonators with longitudinal support is 6% higher than that of the transverse support structure, but the far-field divergence angle is 9% larger than that of the transverse support structure. Although the water-cooled transverse support structure has energy shielding, its good thermal stability significantly improves the quality of the laser beam. Laser beam with a beam quality factorβ of 1.83 and a divergence angleθ 0.865 of 0.63 mrad is obtained under the transverse support unstable resonator ofM =2.25. Under this condition, the laser single pulse energy is 2.34 J, the laser pulse width is 88.2 ns, and the peak power reaches 26.5 MW.-
Key words:
- DF laser /
- inner cavity /
- positive branch confocal unstable resonator /
- beam quality
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表 1 3种不同放大率的正分支非虚共焦非稳腔结构参数
Table 1. Structural parameters of three sets of positive branch virtual confocal unstable resonator with different magnifications
M R1/ mm R2/ mm D /mm d /mm L/mm 1.65 10727.5 − 6501.5 50 30.2 2113 1.85 9197.8 − 4971.9 50 26.9 2113 2.25 7606.8 − 3380.8 50 22.2 2113 表 2 不同放大率下的理论发散角
Table 2. Theoretical divergence angles for different M
M 1.65 1.85 2.25 θ/ mrad 0.4931 0.4544 0.3451 表 3 不同放大倍率下光束质量因子β数据
Table 3. Beam quality factor β data
M β Transverse support Longitudinal support 1.65 2.05 2.25 1.85 1.98 2.18 2.25 1.83 2.00 -
[1] KLINGBEIL A E, JEFFRIES J B, HANSON R K. Tunable mid-IR laser absorption sensor for time-resolved hydrocarbon fuel measurements[J]. Proceedings of the Combustion Institute, 2007, 31(1): 807-815. doi: 10.1016/j.proci.2006.07.228 [2] KLOSNER M, WU C, HELLER D F. Mid-IR Laser system for advanced neurosurgery[J]. Proceedings of SPIE, 2014, 8928: 89280D. [3] STARECKI F, CHARPENTIER F, DOUALAN J L, et al. Mid-IR optical sensor for CO2 detection based on fluorescence absorbance of Dy3+: Ga5Ge20Sb10S65 fibers[J]. Sensors and Actuators B: Chemical, 2015, 207: 518-525. doi: 10.1016/j.snb.2014.10.011 [4] PHAL Y, YEH K, BHARGAVA R. Mid-IR laser-based polarimetric imaging for polymeric and biological applications[J]. Proceedings of SPIE, 2021, 11656: 1165619. [5] FROLOV Y N, VELIKANOV S D, LAZARENKO V I, et al. Remote laser analyzer for methane sensing in the air of subterranean spaces[J]. Proceedings of SPIE, 2002, 4722: 140-144. doi: 10.1117/12.472258 [6] TÖPFER T, PETROV K P, MINE Y, et al. Room-temperature mid-infrared laser sensor for trace gas detection[J]. Applied Optics, 1997, 36(30): 8042-8049. doi: 10.1364/AO.36.008042 [7] VASIL’EV B I, MANNOUN O. IR differential-absorption lidars for ecological monitoring of the environment[J]. Quantum Electronics, 2006, 36(9): 801-820. doi: 10.1070/QE2006v036n09ABEH006577 [8] VELIKANOV S D, ELUTIN A S, KUDRYASHOV E A, et al. Use of a DF laser in the analysis of atmospheric hydrocarbons[J]. Quantum Electronics, 1997, 27(3): 273-276. doi: 10.1070/QE1997v027n03ABEH000923 [9] BRUNET H, MABRU M, VANNIER C. Improved DF performance of a repetitively pulsed HF/DF laser using a deuterated compound[J]. Proceedings of SPIE, 1997, 3092: 494-497. doi: 10.1117/12.270115 [10] SERAFETINIDES A A, RICKWOOD K R, PAPADOPOULOS A D. Performance studies of a novel design atmospheric pressure pulsed HF/DF laser[J]. Applied Physics B, 1991, 52(1): 46-54. doi: 10.1007/BF00405686 [11] IGNAT'EV A B, KAZANTSEV S Y, KONONOV I G, et al. On the possibility of controlling the wave front of a wide-aperture HF(DF) laser by the method of Talbot interferometry[J]. Quantum Electronics, 2008, 38(1): 69-72. doi: 10.1070/QE2008v038n01ABEH013546 [12] PAN Q K, XIE J J, WANG CH R, et al. Non-chain pulsed DF laser with an average power of the order of 100 W[J]. Applied Physics B, 2016, 122(7): 200. doi: 10.1007/s00340-016-6475-z [13] 顾文珊, 梁小溪, 李红超, 等. 小型化轴流式非链式脉冲氟化氘 器[J]. 红外与 工程,2021,50(1):20200082. doi: 10.3788/IRLA20200082GU W SH, LIANG X X, LI H CH, et al. Miniaturized axial flow non-chain pulsed deuterium fluoride laser[J]. Infrared and Laser Engineering, 2021, 50(1): 20200082. (in Chinese). doi: 10.3788/IRLA20200082 [14] TARASENKO V F, PANCHENKO A N. Efficient discharge-pumped non-chain HF and DF lasers[J]. Proceedings of SPIE, 2006, 6101: 61011P. doi: 10.1117/12.643226 [15] APOLLONOV V V, KAZANTSEV S Y, SAIFULIN A V, et al. Discharge characteristics in a Nonchain HF(DF) laser[J]. Quantum Electronics, 2000, 30(6): 483-485. doi: 10.1070/QE2000v030n06ABEH001747 [16] VELIKANOV S D, EVDOKIMOV P A, ZAPOL'SKY A F, et al. Pulse periodic HF (DF)-laser of atmospheric pressure with pulse repetition rate up to 2200 Hz[J]. Proceedings of SPIE, 2008, 7131: 71310V. doi: 10.1117/12.817070 [17] 易爱平, 刘晶儒, 唐影, 等. 放电激励重复频率非链式HF 器[J]. 强 与粒子束,2011,23(7):1763-1766. doi: 10.3788/HPLPB20112307.1763YI A P, LIU J R, TANG Y, et al. Discharge pumped repetition- rate non- chain HF laser[J]. High Power Laser and Particle Beams, 2011, 23(7): 1763-1766. (in Chinese). doi: 10.3788/HPLPB20112307.1763 [18] 朱峰, 黄珂, 周松青, 等. 基于非稳腔的非链式脉冲HF 光束质量优化[J]. 中国 ,2017,44(4):0401002. doi: 10.3788/CJL201744.0401002ZHU F, HUANG K, ZHOU S Q, et al. Laser beam quality optimization of no-chain pulsed HF laser using unstable resonator[J]. Chinese Journal of Lasers, 2017, 44(4): 0401002. (in Chinese). doi: 10.3788/CJL201744.0401002 [19] 阮鹏, 谢冀江, 张来明, 等. 非链式脉冲氟化氘 器的动力学模拟和实验研究[J]. 中国 ,2013,40(7):0702002. doi: 10.3788/CJL201340.0702002RUAN P, XIE J J, ZHANG L M, et al. Dynamical simulation and experimental study of non-chain pulsed DF laser[J]. Chinese Journal of Lasers, 2013, 40(7): 0702002. (in Chinese). doi: 10.3788/CJL201340.0702002 [20] 黄超, 黄珂, 易爱平, 等. 200 W重复频率中红外氟化氢化学 器[J]. 中国 ,2019,46(8):0801005. doi: 10.3788/CJL201946.0801005HUANG CH, HUANG K, YI A P, et al. 200 W Mid-infrared HF chemical laser with repetition rate[J]. Chinese Journal of Lasers, 2019, 46(8): 0801005. (in Chinese). doi: 10.3788/CJL201946.0801005 [21] APOLLONOV V V, BELEVTSEV A A, FIRSOV K N, et al. Advanced studies on powerful wide-aperture nonchain HF(DF) lasers with a self-sustained volume discharge to initiate chemical reaction[J]. Proceedings of SPIE, 2003, 5120: 529-541. [22] 谭改娟, 谢冀江, 潘其坤, 等. 非链式脉冲DF 器非稳腔设计与实验研究[J]. 中国 ,2014,41(1):0102004. doi: 10.3788/CJL201441.0102004TANG G J, XIE J J, PAN Q K, et al. Design and experimental investigation on unstable resonator for non-chain pulsed DF laser[J]. Chinese Journal of Lasers, 2014, 41(1): 0102004. (in Chinese). doi: 10.3788/CJL201441.0102004