High-power passively mode-locked cryogenic Yb:YLF laser

Area of Science:

• Laser Physics
• Materials Science
• Cryogenics

Background:

• Yb:YLF is a promising gain medium for high-power lasers.
• Operation at cryogenic temperatures can improve laser performance by reducing thermal effects.
• Previous studies have not explored mode-locked Yb:YLF at low temperatures.

Purpose of the Study:

• To achieve mode-locked operation of Yb:YLF gain media at cryogenic temperatures.
• To investigate the performance characteristics of such a system.
• To compare the results with existing room-temperature Yb:YLF lasers.

Main Methods:

• Utilized a saturable Bragg reflector for initiating and sustaining mode locking.
• Operated the Yb:YLF gain medium at cryogenic temperatures.
• Employed an intracavity birefringent filter for wavelength tuning.
• Used output couplers in the 10-40% range.

Main Results:

• Achieved self-starting and robust mode-locked operation.
• Generated 3-5 picosecond pulses with average power up to 28 W.
• Reached pulse energies of 602 nJ and peak powers of 126.5 kW at a 46.45 MHz repetition rate.
• Tuned the central wavelength between 1013.5-1019 nm.
• Demonstrated output power two to three orders of magnitude higher than room-temperature systems.

Conclusions:

• Cryogenic temperatures enable significantly enhanced output power for mode-locked Yb:YLF lasers.
• The developed system is robust and self-starting, offering high pulse energy and power.
• This work paves the way for next-generation high-power ultrashort pulse laser systems.