High-power Er:YAG laser with quasi-top-hat output beam

Area of Science:

• Laser Physics
• Quantum Optics
• Materials Science

Background:

• Generating specific laser beam profiles is crucial for various applications.
• Simultaneously exciting multiple transverse modes can create unique beam shapes.
• Er:YAG lasers offer potential for specific wavelength applications but require efficient pumping methods.

Purpose of the Study:

• To report a simple method for simultaneously exciting the fundamental (TEM00) and first-order Laguerre-Gaussian (LG01) donut mode.
• To achieve a quasi-top-hat output beam profile.
• To apply and demonstrate this method in an end-pumped Er:YAG laser system.

Main Methods:

• Utilizing a simple method for simultaneous mode excitation in an end-pumped solid-state laser.
• Employing an Er,Yb fiber laser for in-band pumping of the Er:YAG laser.
• Characterizing the output beam profile and measuring power and beam quality.

Main Results:

• Successfully generated a quasi-top-hat output beam.
• Achieved 9.6 W of continuous-wave output power at 1645 nm.
• Obtained a beam propagation factor (M2) < 2.1 with a slope efficiency of 49% for 24 W of incident pump power.

Conclusions:

• The developed method is effective for creating quasi-top-hat beams.
• The approach shows promise for scaling output power and improving efficiency in solid-state lasers.
• This technique offers a viable route for generating specialized laser beams for diverse applications.