Polarization-tunable Yb:KGW laser based on internal conical refraction

Area of Science:

• Laser Physics
• Optics and Photonics
• Materials Science

Background:

• Standard Ytterbium-doped Potassium Gadolinium Tungstate (Yb:KGW) lasers are widely used for various applications.
• Control over laser polarization states and extinction ratios often requires complex intracavity optical elements.
• Developing simpler methods for polarization control can enhance laser versatility and reduce system complexity.

Purpose of the Study:

• To demonstrate a Yb:KGW laser with tunable polarization states using internal conical refraction.
• To investigate the achievable extinction ratios and output power performance of this novel laser design.
• To assess if the new laser design can match the performance of conventional Yb:KGW lasers.

Main Methods:

• Utilized the phenomenon of internal conical refraction within the Yb:KGW crystal.
• Engineered the laser cavity to exploit internal conical refraction for polarization manipulation.
• Measured output power, slope efficiency, and extinction ratio without adding extra optical components.

Main Results:

• Successfully demonstrated arbitrary alteration of the laser's polarization state.
• Achieved adjustable extinction ratios ranging from 1:1 to 40:1.
• Obtained a maximum output power of 8.6 W with a slope efficiency of 60.5%, comparable to standard lasers.

Conclusions:

• Internal conical refraction provides an effective method for intracavity polarization control in Yb:KGW lasers.
• The demonstrated laser offers tunable polarization and extinction ratios without additional optical elements.
• The power performance of this novel laser design is on par with conventional Yb:KGW lasers.