34.3 W, 172 µJ, 1342 nm picosecond master oscillator power amplifier

Area of Science:

• Optics and Photonics
• Laser Physics
• Materials Science

Background:

• Picosecond lasers are crucial for various scientific and industrial applications.
• High-power, high-energy sources at 1.34 µm are in demand.
• Thermal effects in laser crystals can limit performance.

Purpose of the Study:

• To demonstrate a high-power, high-energy 1342 nm picosecond master oscillator power amplifier (MOPA) laser system.
• To achieve the highest average power for 1.34 µm picosecond lasers.
• To maintain excellent beam quality and power stability.

Main Methods:

• Utilized a SESAM mode-locked oscillator and a regenerative amplifier.
• Employed four main amplification stages (two double-pass, two single-pass).
• Used low-doping Nd:YVO4 crystals with undoped end caps and 880 nm laser diode in-band pumping to mitigate thermal effects.
• Implemented a spherical aberration self-compensation method for beam quality maintenance.

Main Results:

• Achieved 710 µJ pulse energy at 10 kHz from the regenerative amplifier.
• Generated 34.3 W average power, 15.4 ps pulse duration, 172 µJ pulse energy, and 11 MW peak power at 200 kHz.
• Attained the highest average power for 1.34 µm picosecond lasers to date.
• Maintained good beam quality with an M² factor of ~1.31.
• Demonstrated power stability with RMS = 0.89% over 3 hours.

Conclusions:

• The developed Nd:YVO4 MOPA laser system represents a significant advancement in high-power picosecond laser technology.
• The system's performance metrics, including record average power, beam quality, and stability, make it suitable for demanding applications.
• The employed techniques effectively mitigate thermal effects, enabling high-power operation.