Linearly polarized, narrow-linewidth, and tunable Yb:YAG thin-disk laser

Area of Science:

• Optics and Photonics
• Laser Physics
• Materials Science

Background:

• Intracavity laser control is crucial for optimizing laser performance.
• Existing methods for polarization and wavelength selection can be complex or inefficient.
• Yb:YAG thin-disk lasers offer high-power potential but require advanced beam control.

Purpose of the Study:

• To design, fabricate, and implement novel grating-waveguide structures (GWS).
• To utilize GWS for intracavity polarization, wavelength selection, and tuning in Yb:YAG lasers.
• To evaluate the performance and high-power suitability of the GWS.

Main Methods:

• The GWS combines a low-index leaky-mode waveguide, subwavelength diffraction grating, and a reflective mirror in Littrow configuration.
• The GWS was integrated as the end mirror in an Yb:YAG thin-disk laser system.
• Laser output power, bandwidth, polarization, and efficiency were measured under various operating conditions.

Main Results:

• Achieved laser emission with a narrow bandwidth of ≈25 pm FWHM and high linear polarization (99±0.5%).
• Demonstrated a wide wavelength tuning range from 1007 to 1053 nm.
• Confirmed high-power suitability with 325 W multimode and 110 W fundamental-mode output, reaching 1.8 kW with high power density.

Conclusions:

• The developed GWS effectively controls laser polarization and wavelength with high efficiency.
• The GWS is suitable for high-power laser applications, offering significant improvements over conventional methods.
• This technology advances intracavity laser control for Yb:YAG and potentially other laser systems.