Efficient, 15-W output power, diode-end-pumped Nd:YAG laser

Area of Science:

• Optics and Photonics
• Laser Physics
• Materials Science

Background:

• Diode-pumped solid-state lasers offer high efficiency and compact designs.
• Neodymium-doped yttrium aluminum garnet (Nd:YAG) is a common gain medium for lasers.
• End pumping configurations are crucial for efficient energy deposition.

Purpose of the Study:

• To design and evaluate a high-power, diode-pumped continuous-wave (cw) Nd:YAG laser.
• To investigate the performance characteristics of the laser system.
• To identify limitations on single-mode output power.

Main Methods:

• Utilized geometrically multiplexed end pumping with four 10-W diode-laser bars.
• Deposited pump power into the active medium with 80% efficiency.
• Characterized laser performance including threshold, slope efficiency, and overall electrical efficiency.

Main Results:

• Achieved 15-W output power from the Nd:YAG laser.
• Demonstrated a threshold of 3 W and an optical slope efficiency of 60%.
• Observed an overall electrical efficiency of 10.5% and identified thermal aberrations limiting TEM(00) mode power to ~6 W.

Conclusions:

• Geometrically multiplexed end pumping is effective for high-power diode-pumped Nd:YAG lasers.
• Thermal effects, specifically spherical aberration, are a significant factor limiting single-mode output.
• Further optimization is needed to overcome thermal lensing for higher TEM(00) power.