Multiphysics model of liquid-cooled Nd:phosphate split-slabs in large aperture optical amplifiers

Area of Science:

• Laser Physics
• Optical Engineering
• Computational Physics

Background:

• High repetition rates in high-energy solid-state lasers cause amplifier temperature increases, impacting performance through thermal stress, birefringence, and lensing.
• Existing cooling systems may not fully mitigate these thermal effects, necessitating advanced modeling.

Purpose of the Study:

• To develop and validate a multiphysics model for designing and optimizing liquid-cooled, large-aperture, split-slab laser glass amplifiers.
• To predict amplifier performance from optical pumping to amplified wavefront under operational conditions.

Main Methods:

• A multiphysics model integrating optical pumping, heat loading, coolant hydraulics, and mechanical deformation was developed.
• Coupled effects on the optical wavefront were incorporated.
• Model accuracy was verified through specific experimental measurements and characterizations.

Main Results:

• The multiphysics model accurately predicts the performance of a liquid-cooled amplifier.
• Predictions cover the entire process from flash-lamp emission to the amplified wavefront.
• Successful prediction was demonstrated at a repetition rate of one shot per minute.

Conclusions:

• The developed multiphysics model is a valuable tool for the design, optimization, and commissioning of high-energy laser amplifiers.
• This modeling approach effectively addresses thermal management challenges in high-power laser systems.
• Accurate performance prediction enables improved reliability and efficiency of laser amplifiers.