Rall PL, Pflaum C (2021)
Publication Type: Conference contribution, Conference Contribution
Publication year: 2021
Original Authors: Phillip Lino L. Rall, Christoph Pflaum
Event location: Online
DOI: 10.1117/12.2600184
A framework for simulation and compensation of thermal lensing in general optical systems is presented. In high-power optical systems, the beam itself can serve as a non-neglectable heat source, altering the properties of the optical system. For estimating the influence on the optical system, a ray tracing algorithm is used and coupled with a finite element framework. Ray tracing is used to model the optical beam and evaluate the properties of the system. The finite element framework is used to solve the heat and the linear elasticity equation. From the solution of the heat equation, the inhomogeneous refractive index distribution is obtained. Refractive index gradients make it necessary to solve the ray equation iteratively on the finite element mesh. Additionally, the linear elasticity equation results in a displacement vector, which gives the deformation of the optical elements. To solve the ray equation and consider the surface deformation, efficient continuous data interpolation on the finite element mesh is crucial, as the interpolation is a limiting factor for the overall computational performance. This could be achieved by using direct interpolation on the finite element mesh, which reduces memory requirement while improving the interpolation accuracy. With the help of this simulation framework, optical setups which completely compensate for thermal lensing could be found. This could be achieved by a combination of optical materials with positive and negative temperature coefficients and suitable coating parameters, such that the overall thermal lens, resulting form deformation and temperature gradients, is completely compensated. This is a highly coupled problem, as the optical beam, the thermal gradients, and the material deformation affect each other. Hence an iterative simulation setup is necessary, which simulates the optical system until a stable state is found.
APA:
Rall, P.L., & Pflaum, C. (2021). Simulation and compensation of thermal lensing in high power optical systems. In Proceedings of the SPIE Optical Systems Design 2021. Online.
MLA:
Rall, Phillip Lino, and Christoph Pflaum. "Simulation and compensation of thermal lensing in high power optical systems." Proceedings of the SPIE Optical Systems Design 2021, Online 2021.
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