Studies on the Thermal Effect Managements in the Laser-Diode Pumped Solid-State Laser Module

1.前言激光二极管泵浦的高平均功率固体激光驱动器模块在研制激光聚变能量(IFE)时，需要补偿激光介质和有源光学元件中的热透镜、热双折射和热变形等热效应。在本研究中，首次开发了三维热效应分析程序，并通过与实验结果的比较，对程序进行了改进。然后利用该代码重新设计了二极管泵浦固体激光器(DPSSL)驱动模块2。DPSSL驱动模块的设计、开发与评估设计了最小输出能量(10J×10H_2)核聚变用高平均功率激光(HALNA)-10DPSSL驱动模块。在此基础上，提出了一种考虑热效应影响的高功率…阵列的热效应评价方法对建造的HALNA-10DPSSL的输出特性进行了实际测量，与理论计算结果吻合较好。然而，在实现10赫兹工作时，为了补偿热干涉，必须补偿热透镜效应。对于平均功率小于10W的偏振器，用四分之一波长板来测量激光介质和有源光学元件中热双折射的二维分布是有效的。改进了三维热效应平板程序(THESLAC)，并对实验结果进行了解释。设计了HALNA-10~20 DPSSL(10J~20J×10H_2)，结果表明，在10赫兹的输出能量将达到10J~20J。法拉第旋转体和普克尔斯池中热致双折射效应的比较--当100W~1kW 1053 nm激光通过法拉第旋转体玻璃时，实验中的退偏损耗有望超过10%。然而，这种去极化损失将通过在法拉第玻璃之间使用67.5度的石英旋转器来补偿。研究表明，当通过100W级1064 nm的激光时产生的热双折射可以通过使用90度的石英旋转器来补偿。结论HALNA-10DPSSL产生的热效应是可压缩的。然后，我们有信心下一个HALNA 10~20DPSSL将以10赫兹的频率运行。开发的THESLAC代码将在开发工业用高平均功率DPSSL时有用

1.IntroductionWhen a laser-diode-pumped high-average-power solid-state laser driver module Is deveroped for the laser-tnertial -fusion energy (IFE), thermal effect, such as thermal lerislng, thermal birefringence and thermal deformation, in the laser medium and the active optical elements should be compensated for. In this studies, a 3D thermal-effect analysis code is first developed, and by comparing with experimental results the code is improved. After then by use of the code the diode-pumped solid-state laser (DPSSL) driver module is newly designed2. Design, Development and Evaluation of a DPSSL Driver ModuleA smallestoutput energy (10J x 10 H_2) HALNA (High Average-power Laser for Nuclear-fusion Application)-10 DPSSL driver module was destgned. A jet-water cooled laser-diode (LD) array was newly developed which is also useful to pump the future HALNA DPSSL.Then an evaluation method with thermal effects was developed for high-power LD arraysA high-everage power 100-W class DPSSL als … More o developed for IFE as well as for industryOutpul cliaracterisus of constructed HALNA-10 DPSSL were measured in deail, and a good agreement with the theoretical calculation was obtained. However, in oder tu reallze the 10 Hz operation, st is turned out that the thermal lens effect should be compensated forTo tompensate for the thermal btrefringence, It was shown that a quarter wavelength plate was useful for the DPSSL of less than 10W average powerA polarimeter to measure the 2D distribution of thermal birefrigence in the laser medium and the active optical elements, was newly developed3D thermal effects slab code (THESLAC) was tmproved and this THESLAC code explained the experlmental results3. Designlog HALNA-10〜20 DPSSL (10J〜20J×10 H_2) was designed, and it was shown the 10J〜20J output energy at 10 Hz will be acheaventBy use of the THESLAC code, a HALNA-10〜20 DPSSL (10J〜20J×10 H_2) was designed, and it was shown the 10J〜20J output energy at 10 Hz will be acheavent4. Conipensatlon of Therinal Birefrigence in the Faraday Rotator and Pockels CellWheti passing the 100 W〜1 kW 1053-nm laser light through a Faraday rotator glass, a depolarization loss over 10 % was expected experimentalty. However, such depolatization loss will be compensated for by use of a 67.5-degree quartz rotator between Faraday glassesIt was shown that the thermal birefringence, generated when passing the 100W class laser light at 1064 nm, can be compensated for by use of a 90-degree quartz rotator5. ConclusionIt was shown that the thermal effects generated in ihe HALNA-10 DPSSL can be comperisalable. Then, we have a confidence that next HALNA 10 〜 20 DPSSL will be operated at 10 Hz. The THESLAC code developed will be useful when developing the high-average power DPSSLs for industry Less