3D Ray Tracing Model for Laser Beam influenced by Thermal Lensing


Details zur Publikation

Autorinnen und Autoren: Rall PL, Springer R, Pflaum C
Jahr der Veröffentlichung: 2017


In the last few decades, research on new laser systems with high output power has

strongly progressed. The required pump power for such high power lasing also induces

a significant amount of heat load within the gain medium. This thermal influence

leads to different effects, the most important are thermal lensing, beam degradation

and depolarization. The prupose of this thesis is to develop a ray tracing model for

the simulation of thermal lensing, beam degradation and depolarization in single pass

solid state amplifiers. The therefore necessary theory is given in the first part of the

thesis. The simulation model, which traces rays through the thermally influenced media,

is described in detail, just as the evaluation of the data for determining the thermal

focal length, beam degradation and depolarization. With this model, the influences

of pump and seed beam size, quantum defect and heat distribution, crystal properties

and amplifier dimensions are investigated. Those give a general idea how to prevent and

compensate for the thermal effects in amplifiers. The thermally induced focal power was

shown to rise linear with the pump power and decreases linear with the quantum defect.

Also the dioptric power decreases exponentially with increasing pump beam radius. The

most dominant influences on the beam quality degradation are the ratio between seed

and pump radius, the pump beam shape and the pump power as well. Ratios of seed

to pump close to unity lead to stronger beam degradation, while too small ratios may

significantly decreases the efficiency of the amplifier. Since ray tracing is already an

approximation of the actual ray trajectory, its limits are investigated carefully. Other

effects, such as gain guiding or gain saturation, are not included in this simulation,

which further limit the simulation results. However, if those limits are not exceeded, the

simulation gives good results, as is shown by comparison with experimental data.

FAU-Autorinnen und Autoren / FAU-Herausgeberinnen und Herausgeber

Pflaum, Christoph Prof. Dr.
Professur für Informatik (Numerische Simulation mit Höchstleistungsrechnern)
Rall, Phillip Lino
Lehrstuhl für Informatik 10 (Systemsimulation)
Springer, Ramon
Professur für Informatik (Numerische Simulation mit Höchstleistungsrechnern)

Zusätzliche Organisationseinheit(en)
Lehrstuhl für Informatik 10 (Systemsimulation)


Rall, P.L., Springer, R., & Pflaum, C. (2017). 3D Ray Tracing Model for Laser Beam influenced by Thermal Lensing (Master thesis).

Rall, Phillip Lino, Ramon Springer, and Christoph Pflaum. 3D Ray Tracing Model for Laser Beam influenced by Thermal Lensing. Master thesis, 2017.


Zuletzt aktualisiert 2019-03-04 um 10:23