High-power dual-rod Yb:YAG laser

Area of Science:

• Laser Physics
• Materials Science
• Optical Engineering

Background:

• Diode-pumped solid-state lasers offer high efficiency and compactness.
• ytterbium-doped Yttrium Aluminum Garnet (Yb:YAG) is a promising gain medium for high-power lasers.
• Achieving high beam quality at high output power is a key challenge in laser development.

Purpose of the Study:

• To develop and characterize a high-power diode-pumped Yb:YAG laser.
• To investigate the relationship between resonator parameters, output power, and beam quality.
• To demonstrate efficient power extraction and beam shaping.

Main Methods:

• Utilized two composite Yb:YAG rods with bifocusing compensation using a quartz rotator.
• Employed microlensed diode array end-pumping with hollow lens ducts for efficient pump delivery.
• Adjusted resonator parameters to control fundamental mode size and output beam quality.
• Compared experimental results with a model predicting output power versus beam quality based on mode-fill efficiency and clipping losses.

Main Results:

• Achieved 1080 W continuous wave (cw) output power with 27.5% optical-optical efficiency.
• Generated 532 W Q-switched power with M(2)=2.2 and 17% optical-optical efficiency.
• Demonstrated tunability of output beam quality by adjusting resonator parameters.

Conclusions:

• The developed diode-pumped Yb:YAG laser system is capable of high-power output in both cw and Q-switched regimes.
• The employed bifocusing compensation and pump delivery methods are effective for high-power operation.
• The study provides valuable data for optimizing laser design for specific beam quality requirements.