125-mJ diode-pumped injection-seeded Ho:Tm:YLF laser

Area of Science:

• Laser Physics
• Optical Engineering
• Remote Sensing

Background:

• Developing efficient and high-quality laser sources is crucial for advanced remote sensing applications like coherent wind lidar.
• Holmium-doped, Thulium-doped Yttrium Lithium Fluoride (Ho:Tm:YLF) lasers offer potential for specific wavelength applications but require optimization for power and beam quality.

Purpose of the Study:

• To develop and characterize a diode-pumped, room-temperature Ho:Tm:YLF power oscillator.
• To investigate the laser's performance under varying conditions, including temperature and pump intensity.
• To assess the suitability of the laser for space-based coherent wind lidar.

Main Methods:

• Utilized a diode-pumped, room-temperature Ho:Tm:YLF crystal for laser oscillation.
• Employed Q-switching to achieve high peak power and specific pulse characteristics.
• Implemented injection seeding to obtain single-frequency, nearly transform-limited output.
• Investigated laser performance by varying laser rod temperature and pump intensity.

Main Results:

• Achieved an optical-to-optical efficiency of 0.03.
• Obtained a Q-switched output energy of up to 125 mJ at a 6 Hz repetition rate with a 170 ns pulse width.
• Demonstrated single-frequency, nearly transform-limited laser operation through injection seeding.
• Characterized laser performance across different operating parameters.

Conclusions:

• The developed Ho:Tm:YLF laser exhibits promising performance for high-power, high-beam-quality requirements.
• The laser's characteristics, particularly its single-frequency and transform-limited output, are well-suited for coherent wind lidar.
• This laser technology is a strong candidate for deployment as a transmitter on space platforms for wind sensing.