Polarization-multiplexed 100 Hz high-energy Nd:YAG multipass slab amplifier.

Area of Science:

• Laser physics and engineering
• Optical amplification systems
• Solid-state laser technology

Background:

• Next-generation space and Earth observation missions require high-energy, high-throughput laser systems.
• Existing laser amplifiers face challenges in efficiency, thermal management, and energy extraction.

Purpose of the Study:

• To realize and characterize a high-efficiency diode-pumped solid-state amplifier for demanding applications.
• To develop a master oscillator power amplifier (MOPA) architecture capable of high energy extraction and stable operation.

Main Methods:

• Utilized a Brewster-cut Nd:YAG slab amplifier with an internal optical zigzag path for optimized pump- இது overlap.
• Implemented a polarization-multiplexed three-pass scheme for enhanced energy extraction.
• Characterized amplifier performance in Q-switching (QS) regime at 1064 nm.

Main Results:

• Achieved robust energy extraction exceeding 200 mJ per pulse at 100 Hz pulse repetition frequency (PRF).
• Demonstrated root mean square (RMS) average power fluctuations below 0.25%.
• Exhibited a residual thermal focal length greater than 1 m, indicating effective thermal management.

Conclusions:

• The developed Nd:YAG slab amplifier represents a novel side-pumped design with a zigzag optical path and polarization multiplexing.
• This system is the first of its kind to exceed 200 mJ extraction energy at 100 Hz PRF in QS regime.
• The amplifier is well-suited for high-energy laser applications in space and Earth observation.