Combined guiding effect in the end-pumped laser resonator

Area of Science:

• Laser Physics and Optics
• Nonlinear Optics
• Computational Physics

Background:

• Transverse mode formation in laser resonators is crucial for beam quality.
• Existing models often simplify or neglect combined thermal and gain guiding effects.
• High-power end-pumped lasers present unique challenges due to thermal lensing and gain saturation.

Purpose of the Study:

• To theoretically model and experimentally verify a combined guiding mechanism for transverse mode formation.
• To investigate the interplay of thermal refractive index guiding and gain guiding effects.
• To establish a theoretical framework applicable to high-power end-pumped laser resonators.

Main Methods:

• Derivation of a nonlinear Schrödinger-type wave equation incorporating thermal and gain guiding.
• Numerical solution using the split-step Fourier method.
• Experimental setup of a high-power end-pumped Nd:YVO4 laser resonator with thermal analysis.

Main Results:

• The combined guiding effect was successfully observed and experimentally verified for the first time.
• Experimental transverse mode profiles closely matched predictions from the derived nonlinear wave equation.
• The developed wave theory accurately describes transverse mode formation in high-power end-pumped laser resonators.

Conclusions:

• The combined thermal and gain guiding mechanism is the dominant factor in transverse mode formation.
• The theoretical model provides a robust tool for designing and optimizing high-power laser resonators.
• This work advances the understanding and engineering of laser beam characteristics.