Single frequency MOPA based on Nd:YAG single crystal fiber and rods

Area of Science:

• Optics and Photonics
• Laser Physics
• Materials Science

Background:

• High-power, single-frequency lasers are crucial for various scientific and industrial applications.
• Existing laser systems often face limitations in power, pulse characteristics, or beam quality.
• The development of efficient master oscillator power amplifier (MOPA) architectures is key to overcoming these limitations.

Purpose of the Study:

• To design and demonstrate a single-frequency 1064 nm MOPA system.
• To achieve high output power and energy using a macro-micro pulse scheme.
• To characterize the laser output, including power, pulse duration, linewidth, and beam quality.

Main Methods:

• A single-longitudinal-mode electro-optically Q-switched Nd:YAG laser served as the master oscillator.
• A three-stage power amplifier configuration utilizing Nd:YAG single crystal fiber and rods was employed.
• The system operated in a macro-micro pulse scheme with specific repetition rates and pulse durations.

Main Results:

• The MOPA system achieved a final output power of 31.3 W with a pulse duration of 30 ns and a linewidth < 130 MHz.
• Micro pulse energy reached 13.9 mJ, resulting in a peak power of up to 464 kW.
• Excellent beam quality was confirmed with M² factors of 1.56 (horizontal) and 1.76 (vertical).

Conclusions:

• The demonstrated Nd:YAG MOPA system effectively delivers high-power, single-frequency laser output.
• The macro-micro pulse scheme enables efficient energy extraction and high peak power generation.
• The system's performance characteristics make it suitable for demanding laser applications requiring precise control and high energy.