3D ray tracing model for laser beams influenced by thermal lensing in solid-state gain media
3D ray tracing model for laser beams influenced by thermal lensing in solid-state gain media
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DOI：
10.1117/12.2311840
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发表时间：
2018-05
期刊：
影响因子：
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通讯作者：
Phillip Lino Rall;Ramon Springer;C. Pflaum
中科院分区：
文献类型：
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作者：
Phillip Lino Rall;Ramon Springer;C. Pflaum
提出了一种热效应固态单程放大器的光线跟踪模型，该模型能够模拟热透镜效应、退偏振和光束质量退化。射线跟踪算法基于交替评估轴向和径向梯度，从而在受热影响的介质中找到轨迹。这使得能够找到系统的焦距分布。此外，还根据光线的位置确定其相位，从而能够重建通过晶体后的光束的波前。此波前用于Zernike多项式分析，以确定球差，球差与通过光束的光束质量有关。此外，通过分别求出每条光线的偏振变化，即可得到总的退偏振。对热透镜的模拟与单程Nd：YVO4系统进行了比较，并与Nd：YVO4-MOAP系统的光束退化进行了比较。只要系统的增益是均匀的，两者都与仿真数据吻合很好。
A ray tracing model for thermal effects solid-state single-pass amplifiers is presented, which is able to simulate thermal lensing, depolarization and beam quality degradation. The ray tracing algorithm is based on alternatively evaluating the axial and radial gradient and thereby finding the trajectory in thermally influenced media. This enables to find the focal length distribution of the system. Additionally, to the position of the rays, its phase is also determined, which enables to reconstruct the wavefront of the beam after passing through the crystal. This wavefront is used for a Zernike polynomial analysis to determine spherical aberration, which is linked to the beam quality of the passing beam. Furthermode the total depolarization is obtained by finding the change of polarization for each ray separately. The simulation for thermal lensing is compared with a single-pass Nd:YVO4 system, the beam degradation is compared with a Nd:YVO4-MOAP system. Both show good agreement with the simulation data, as long as the gain of the system is homogeneous.